Illegal modifications to cars in the UK

You want to stay safe and legal when you make modifications to your car so you really need to know where the law stands on each modification you’re thinking of making. Illegal modifications to cars in the UK will get you in trouble with the law but they’ll also invalidate your car’s insurance.

In car entertainment

This is an area that most people don’t consider to be modding but you’re still party to a whole load of rules and regulations when you change the car’s entertainment systems. Any moving images that are within view of the driver are illegal whilst driving as they cause distraction, so that’s something to be aware of.

Wheels and tyres

Changing the car’s wheels and tyres can have a major impact on its styling but there are also performance and safety questions to consider. When fitting bigger wheels make sure they’re approved by the car’s manufacturer. There also has to be adequate clearance between the tyres and the bodywork if you want your car to remain legal.


Lowering suspension is another common mod that drivers like to make. Putting stiffer springs in and lower the car’s ride height will compromise the vehicle’s handling. You’ll need to get the work carried out by a competent mechanic to make sure that your car remains road worthy.


Modifying the brakes can lead to obvious hazards. Again, a competent engineer is needed to make sure your new brakes are fitted safely and legally. Don’t forget that modifying your car often leads to greater attention from traffic police so if there are any issues with the car’s road worthiness, they’ll be picked up pretty quickly after your car hits the tarmac.

Car lights

If you’d like to know if lights under a car are legal in the UK, click here.

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