Life

The illegal car modifications that you may not know about

Many car enthusiasts like to modify their cars in a way to improve the look, power and performance, however, some enhancements can be illegal.

Car enthusiasts love to modify their cars with engine upgrades and louder exhausts. (Audi)
Car enthusiasts love to modify their cars with engine upgrades and louder exhausts. (Audi) Car enthusiasts love to modify their cars with engine upgrades and louder exhausts. (Audi)

This week has seen the famous British rapper, Stormzy, plead guilty to driving his Lamborghini Urus with illegally tinted windows.

It may not sound like a modification – or ‘mod’ – but anything that is installed on your vehicle that hasn’t been fitted by the manufacturer or dealership is classed as one.

In the UK, there are legal requirements for the amount of tint on a car’s front windows. A total of 70 per cent of the glass must be clear, however the rapper’s Lamborghini was showing as little as four per cent visibility. Additionally, the front windscreen needs to be at least 75 per cent clear, too. However, there is no law for how dark the rear side and back windows need to be.

So dark front tinted windows are illegal. But what other car modifications are breaking the law? And what should you do to prevent yourself from landing a big fine?  Here is a list of car modifications that are illegal here in the UK.

Neon lights



Neons are projected coloured lights that fit to the underside of your car. In the UK, it is illegal to drive around with them as they can become a hazard to other road users for being distracting.

However, you can buy neon tubing, which as the name suggests are coloured tubes which can be stuck to the underside of your car, or fitted into the interior. Their brightness can be altered which allows these to be legal, which can be an alternative.

Tinted headlights


Having tinted headlights can reduce your vision of the road ahead at night.
Having tinted headlights can reduce your vision of the road ahead at night. (Andrew Milligan/PA)

Normal headlights are white and yellow, while brake lights are red – and this is how they should remain. If you add any other colours to your lights or tint them to any extent, you have a higher risk of being pulled over and being fined.

By tinting your headlights, it can reduce their beam images, which will make it harder for you to see the road ahead when driving at night.

Also, if you fit coloured halogen bulbs, they can be too bright. This could cause other drivers to be blinded by your headlights causing a greater risk of an accident occurring.

Loud exhausts

All new cars must meet 72dB when tested 0.5 meters away from their exhaust pipes. (Audi)
All new cars must meet 72dB when tested 0.5 meters away from their exhaust pipes. (Audi)

Car enthusiasts love the sound of an engine. By fitting larger exhausts allow them to be broadcasted even clearer, however there is a certain noise limit that all road cars need to meet before they are too loud and classed as anti-social.

In the UK, the maximum decibel limit is 74dB, but for all new vehicles, the limit is 72. This applies to cars, motorbikes and vans. The sound is measured from a distance of 0.5 metres away from the exhaust pipes and if they exceed the noise limit it will make the vehicle illegal to drive on our roads. The way to get around this is to fit a bigger exhaust silencer or if it’s not the original unit, to revert it back to the stock example.

No one wants to be woken up in the early hours of the morning by someone with an excessively loud exhaust. Meanwhile, the UK has also introduced noise cameras in a number of areas to try and stop and fine people with unnecessary loud exhaust systems fitted to their car or motorbikes.

Poorly fitted spoilers

Spoilers are not illegal, but they can be if they’re not fitted correctly or have sharp edges. (Honda)
Spoilers are not illegal, but they can be if they’re not fitted correctly or have sharp edges. (Honda)

It’s not illegal to fit your car with a spoiler. Its purpose is to increase the downforce at the rear to improve a car’s cornering abilities. However, if it’s not been fitted correctly or if its design has sharp edges and could potentially injure someone, you could be asked by the police to remove it immediately to reduce the chances of it falling off or hurting a member of the public.

Another point to consider if you are thinking of installing one is to check it doesn’t obstruct your rearward view and that it isn’t too large, too.

Nitrous oxide


Nitrous oxide can damage your engine if not tweaked and enhanced properly.
Nitrous oxide can damage your engine if not tweaked and enhanced properly. (Alistair Wilson 50/50/PA)

Adding nitrous oxide gas to your car’s engine may make it a lot quicker and more exciting but it’s also illegal to do so. It’s designed to increase the pressure in your engine’s cylinders to make them work faster, however if you’ve not done your homework and upgraded the engine to take that additional power, you could be at risk of damaging the entire unit altogether. If there’s too much oxygen and not enough fuel in the engine, it can also have the same effect with it failing entirely.