Skip to main content
N I Direct government services

Main navigation

  • Home
  • News
  • Contacts
  • Help
  • Twitter
  • Facebook
  • YouTube
  • RSS

Translation help

Translate this page

Select a language

  • Afrikaans — Afrikaans
  • Albanian — Shqip
  • Amharic — አማርኛ
  • Arabic — العربية
  • Armenian — Հայերեն
  • Assamese — অসমীয়া
  • Aymara — Aymar aru
  • Azerbaijani — Azərbaycan dili
  • Bambara — Bamanankan
  • Basque — Euskara
  • Belarusian — Беларуская
  • Bengali — বাংলা
  • Bhojpuri — भोजपुरी
  • Bosnian — Bosanski
  • Bulgarian — Български
  • Cantonese — 廣州話
  • Catalan — Català
  • Cebuano — Sinugbuanong Binisayâ
  • Chichewa — Chichewa
  • Chinese (Simplified) — 简体中文
  • Chinese (Traditional) — 繁體中文
  • Corsican — Corsu
  • Croatian — Hrvatski
  • Czech — Čeština
  • Danish — Dansk
  • Dhivehi — ދިވެހި
  • Dogri — डोगरी
  • Dutch — Nederlands
  • English — English
  • Esperanto — Esperanto
  • Estonian — Eesti
  • Ewe — Eʋegbe
  • Filipino — Filipino
  • Finnish — Suomi
  • French — Français
  • Frisian — Frysk
  • Galician — Galego
  • Georgian — ქართული
  • German — Deutsch
  • Greek — Ελληνικά
  • Guarani — Avañe’ẽ
  • Gujarati — ગુજરાતી
  • Haitian Creole — Kreyòl ayisyen
  • Hausa — Hausa
  • Hawaiian — ʻŌlelo Hawaiʻi
  • Hebrew — עברית
  • Hindi — हिन्दी
  • Hmong — Hmoob
  • Hungarian — Magyar
  • Icelandic — Íslenska
  • Igbo — Asụsụ Igbo
  • Ilocano — Ilokano
  • Indonesian — Bahasa Indonesia
  • Irish — Gaeilge
  • Italian — Italiano
  • Japanese — 日本語
  • Javanese — Basa Jawa
  • Kannada — ಕನ್ನಡ
  • Kazakh — Қазақ тілі
  • Khmer — ភាសាខ្មែរ
  • Kinyarwanda — Ikinyarwanda
  • Konkani — कोंकणी
  • Korean — 한국어
  • Krio — Krio
  • Kurdish (Kurmanji) — Kurdî
  • Kurdish (Sorani) — کوردی
  • Kyrgyz — Кыргызча
  • Lao — ລາວ
  • Latin — Latina
  • Latvian — Latviešu
  • Lingala — Lingála
  • Lithuanian — Lietuvių
  • Luganda — Luganda
  • Luxembourgish — Lëtzebuergesch
  • Macedonian — Македонски
  • Maithili — मैथिली
  • Malagasy — Malagasy
  • Malay — Bahasa Melayu
  • Malayalam — മലയാളം
  • Maltese — Malti
  • Maori — Māori
  • Marathi — मराठी
  • Meiteilon (Manipuri) — ꯃꯤꯇꯩ ꯂꯣꯟ
  • Mizo — Mizo ṭawng
  • Mongolian — Монгол хэл
  • Myanmar (Burmese) — မြန်မာစာ
  • Nepali — नेपाली
  • Norwegian — Norsk
  • Odia (Oriya) — ଓଡ଼ିଆ
  • Oromo — Afaan Oromoo
  • Pashto — پښتو
  • Persian — فارسی
  • Polish — Polski
  • Portuguese — Português
  • Punjabi — ਪੰਜਾਬੀ
  • Quechua — Runa Simi
  • Romanian — Română
  • Russian — Русский
  • Samoan — Gagana Samoa
  • Sanskrit — संस्कृतम्
  • Scots Gaelic — Gàidhlig
  • Sepedi — Sepedi
  • Serbian — Српски
  • Sesotho — Sesotho
  • Shona — Shona
  • Sindhi — سنڌي
  • Sinhala — සිංහල
  • Slovak — Slovenčina
  • Slovenian — Slovenščina
  • Somali — Soomaali
  • Spanish — Español
  • Sundanese — Basa Sunda
  • Swahili — Kiswahili
  • Swedish — Svenska
  • Tajik — Тоҷикӣ
  • Tamil — தமிழ்
  • Tatar — Татар теле
  • Telugu — తెలుగు
  • Thai — ไทย
  • Tigrinya — ትግርኛ
  • Tsonga — Xitsonga
  • Turkish — Türkçe
  • Turkmen — Türkmençe
  • Twi — Twi
  • Ukrainian — Українська
  • Urdu — اردو
  • Uyghur — ئۇيغۇرچە
  • Uzbek — Oʻzbekcha
  • Vietnamese — Tiếng Việt
  • Welsh — Cymraeg
  • Xhosa — IsiXhosa
  • Yiddish — ייִדיש
  • Yoruba — Yorùbá
  • Zulu — IsiZulu
  • Breadcrumb

    1. Home
    2. Motoring
    3. Owning a vehicle
    4. Advice for vehicle keepers

    Modified cars - what you need to know

    Cars are sometimes modified to improve performance or style. If you're considering modifying your car or you have bought a modified car, you can find information below on modifications including in-car entertainment, lights or reflectors, suspension and brakes.

    Safety first

    Staying safe and legal is extremely important when modifying your car. It is essential to remember that some modifications can make your vehicle unsafe for you, your passengers and other road users. It could also put you on the wrong side of the law and perhaps your insurance company. Remember that you are responsible for making sure that your vehicle is legal and safe to use on the road at all times, regardless of who carried out any modifications.

    In-car entertainment

    Over the last few years there has been a huge increase in the amount of in-car entertainment devices that have become available for the motorist.

    As the driver, your primary responsibility is to stay focused on the road and avoid anything that could distract you.

    • do not let in-car entertainment divert your attention.
    • avoid watching screens visible in the rear-view mirror.
    • do not search through devices such as MP3 players while driving.
    • moving images visible to the driver are illegal while driving.

    It is illegal to drive a vehicle while using a hand-held mobile phone or a similar device.

    More information can be found at the link below:

    • Using your mobile phone while driving

    Lights or reflectors

    Headlamps must show a largely white or yellow light. Rear position lamps must show a steady red light to the rear only. Tinting of rear reflectors which will reduce efficiency is not permitted.

    Replacement bulbs must be road legal, especially in headlamps. Many aftermarket LED bulbs are not road legal and can cause dazzle and glare. This can be dangerous to other road users as it impairs their vision.

    Wheels and tyres

    Changes to wheels and tyres can significantly alter your car's behaviour on the road. 

    It is import to make sure that they:

    • are approved by the vehicle manufacturer
    • give adequate clearance between tyre and bodywork

    Stretched or “euro look” tyres should only be installed where this can be done safely in line with industry guidance.

    • Euro look - tyres and compatibility

    Suspension

    Modifications to the suspension including the fitment of stiffer springs and lowering kits, should only be done where the car's road handling will not be compromised. This work should only be carried out by a proficient person.

    Brakes

    Modifications to your car's brakes must at all times be carried out by a proficient person. Before parting with your money, seek advice from independent suppliers and the vehicle manufacturer to make sure that the brakes you intend fitting are suitable, and won't adversely affect handling or electronic safety systems.

    Tinted windows

    It is illegal to have a windscreen or windows either side of the driver tinted darker than legally allowed . For most cars, that’s 75% for the windscreen and 70% for the windows in the front doors.  Added sun strips must not encroach on the area swept by the original equipment wipers.

    Drivers view

    It is illegal to have anything in a vehicle which affects the drivers view.

    • opaque film including decals should not be installed on the windscreen where they interfere the drivers view in any way
    • be careful not to have any bulky objects hanging from the rear-view mirror
    • take care with positioning of dash cams so they don’t encroach on the drivers view
    • sat navs and mobile phones must not be mounted to the windscreen.

    Spoilers

    Spoilers must not have any sharp edges or hinder your driving or vision and must be securely fitted to the bodywork so as not to detach whilst driving, causing danger or injury to other road users.

    Number plates

    Number plates must:

    • meet with current legislation
    • be displayed in a prominent position
    • be readable by infrared cameras
    • not be misleading or obscured

    Exhaust system

    All exhaust silencers must be maintained in a good and efficient working order. You will be breaking the law if you remove a silencer or make any change that would make that vehicle emit a noise louder than the original exhaust before it was modified.

    Exhaust emissions

    Emission control equipment originally fitted by the manufacturer must be maintained in good working order, and not removed, bypassed or tampered with.

    Examples of improper modifications include: 

    • physically removing equipment such as catalytic converter or diesel particulate filters (DPF) or associated sensors, 
    • bypassing Exhaust Gas Recirculation (EGR) or Selective Catalytic Reduction (SCR, AdBlue) systems,
    • changing control mapping to increase smoke, noise, emissions, or to bypass emissions control systems.

    Information on vehicle smoke emissions, enforcement checks and how a metered diesel smoke test is conducted can be found at link below.

    • More information on emissions

    To read more about car modifications you can download a copy of the 'Modified Cars - what you need to know' leaflet at the link below or you can contact DVA directly.

    • Modified cars - what you need to know information leaflet

     

    More useful links

    • Rules and advice for drivers and riders (103 to 158)
    • Road safety
    Share this page Share on Facebook (external link opens in a new window / tab) Share on X (external link opens in a new window / tab) Share by email (external link opens in a new window / tab)

    Advice for vehicle keepers

    • E10 petrol explained - GOV.UK website
    • If a vehicle, part or accessory has been recalled
    • Maintaining your vehicle
    • Modified cars - what you need to know
    • Release of information from DVA records
    • Tinted vehicle windows - the rules
    • Using your mobile phone while driving
    • Wearing a seat belt and exemptions
    • Your vehicle's smoke emissions standards

    Help improve this page - send your feedback

    What do you want to do?
    Report a problem
    Which problem did you find on this page? (Tick all that apply)

    Messages

    This is the official government website for Northern Ireland. You will not receive a reply. nidirect will consider your feedback to help improve the site. 

    Do not include any personal or financial information, for example National Insurance, credit card, or phone numbers. 

    What is your question about?

    What to do next

    Comments or queries about angling can be emailed to anglingcorrespondence@daera-ni.gov.uk 

    If you have a comment or query about benefits, you will need to contact the government department or agency which handles that benefit.  Contacts for common benefits are listed below.

    Carer's Allowance

    Call 0800 587 0912
    Email 
    dcs.incomingpostteamdhc2@nissa.gsi.gov.uk

    Discretionary support / Short-term benefit advance

    Call 0800 587 2750 
    Email 
    customerservice.unit@communities-ni.gov.uk

    Disability Living Allowance

    Call 0800 587 0912 
    Email dcs.incomingpostteamdhc2@nissa.gsi.gov.uk

    Employment and Support Allowance

    Call 0800 587 1377

    Jobseeker’s Allowance

    Contact your local Jobs & Benefits office

    Personal Independence Payment

    Call 0800 587 0932

    If your query is about another benefit, select ‘Other’ from the drop-down menu above.

    Comments or queries about the Blue Badge scheme can be emailed to bluebadges@infrastructure-ni.gov.uk or you can also call 0300 200 7818.

    For queries or advice about careers, contact the Careers Service.

    For queries or advice about Child Maintenance, contact the Child Maintenance Service.

    For queries or advice about claiming compensation due to a road problem, contact DFI Roads claim unit.

    For queries about your identity check, email nida@nidirect.gov.uk and for queries about your certificate, email covidcertni@hscni.net.

    For queries or advice about criminal record checks, email ani@accessni.gov.uk

    Application and payment queries can be emailed to ema_ni@slc.co.uk

    For queries or advice about employment rights, contact the Labour Relations Agency.

    For queries or comments about a GP practice, contact the practice directly. If information about the GP practice is missing, outdated or wrong, email Business Services Organisation (BSO) at: professionalsupportteam@hscni.net.

    For queries or advice about birth, death, marriage and civil partnership certificates and research, contact the General Register Office Northern Ireland (GRONI) by email gro_nisra@finance-ni.gov.uk

    For queries about your GRONI account, email gro_nisra@finance-ni.gov.uk.

    For queries about the High Street Spend Local Scheme,  email HSSS.mail@economy-ni.gov.uk.

    For queries about:

    • Car tax, vehicle registration and SORN
      contact the Driver and Vehicle Licensing Agency (DVLA), Swansea
       
    • Driver licensing and tests, MOT and vehicle testing, contact the DVA online

    If your query is about another topic, select ‘Other’ from the drop-down menu above.

    For queries about your identity check, email nida@nidirect.gov.uk.

     

    For queries or advice about passports, contact HM Passport Office.

    For queries or advice about Penalty Charge Notices (PCNs), including parking tickets and bus lane PCNs, email dcu@infrastructure-ni.gov.uk

    For queries or advice about pensions, contact the Northern Ireland Pension Centre.

    If you wish to report a problem with a road or street you can do so online in this section.

    If you wish to check on a problem or fault you have already reported, contact DfI Roads.

    For queries or advice about historical, social or cultural records relating to Northern Ireland, use the Public Record Office of Northern Ireland (PRONI) enquiry service.

    For queries or advice about rates, email LPSCustomerTeam@lpsni.gov.uk

    For queries or advice about  60+ and Senior Citizen SmartPasses (which can be used to get concessionary travel on public transport), contact Smartpass - Translink.

    If you have a question about a government service or policy, you should contact the relevant government organisation directly. 

    Related sites

    • gov.uk
    • nibusinessinfo.co.uk

    Links to supporting information

    • Accessibility statement
    • Crown copyright
    • Terms and conditions
    • Privacy
    • Cookies
    • Twitter
    • Facebook
    • YouTube
    • RSS