CAR modifications have become increasingly popular among young drivers eager to personalise their vehicles.
The UK government enforces tight laws to ensure that all vehicles are safe for both the driver, and other road users which mean some car modifications are illegal.
Tinted Windows
Tinted windows can be illegal in the UK if they don’t meet the legal requirements.
According to UK Government laws, the rules for tinted front windscreens and front side windows depend on when the vehicle was first used.
There are no rules for tinting the rear windscreen or rear passenger windows.
For vehicles first used on 1 April 1985 or later, the front windscreen must let at least 75% of light through, and the front side windows must allow at least 70% of light through.
For older vehicles first used before 1 April 1985, both the front windscreen and front side windows must allow 70% of light through.
The police and Driver and Vehicle Standards Agency (DVSA) vehicle examiners use light measuring equipment to assess drivers window tint.
If your windscreen or front side windows are tinted too much you could get:
- A ‘prohibition notice’ stopping you using your vehicle on the road until you have the extra tint removed
- A penalty notice or court summons
Headlight Tinting
Headlight tints, sometimes referred to as smoked headlights, are becoming increasingly more popular.
This modification involves a process of applying a specialised film on the surface of a vehicle’s headlight or rear lights to add a refined aesthetic.
Headlight tints are legal within the UK, within reason.
If the headlights on your car are modified with anymore than a 50% tint, then it will be classified as illegal.
The tint should not alter the colour of the light, they should remain white or yellow respectively at the front, and red at the rear.
Loud exhausts
It’s illegal to modify the exhaust system to make a vehicle noisier after it has been ‘type approved.’
The legal limit for exhaust noise in the UK is 74 decibels, which is roughly no louder than flushing a toilet.
Loud horns
There are limits to the amount of noise that vehicles can make on public roads.
Whilst you can modify your car horn in the UK, it must still sound like a car horn otherwise you might not pass your MOT.
According to the Road Vehicles Regulations 1986, “No motor vehicle shall be fitted with a bell, gong, siren, or two-tone horn.”
Underbody Neon Lights
This is one of the more expensive modifications on the list – but nevertheless neon lights can land you in hot water.
Over the past couple of years, neon lights have grown in popularity on TikTok and Instagram.
There are no laws specifically prohibiting you from fitting neon lighting to the underbody of your car.
However, there are some strict rules on the types of lights you can display and where.
Blue lights cannot be displayed in any direction of your vehicle as they can be confused with an emergency vehicle, according to The Road Vehicles Lighting Regulations.
A white light at the back of the vehicle is also not allowed as this can confuse drivers.
And green lights are banned as they are used by doctors on call so cannot be used by drivers.
Red lights at the front of the car are also prohibited.
A penalty for having the wrong lights can easily be avoided by not using any lights that can confuse drivers and not having a prohibited colour.
But if these rules are ignored you could face a £50 fine or be reported to court.
You should also inform your insurer if you add neon lights to your car, as some modifications can affect your premium.
Personalised Number Plate
Personalised number plates are not just for the rich and famous.
There are strict rules governing the correct display of registration plates.
A personalised number plate must:
- Be made from reflective material
- Display black characters on a white background on the front plate
- Display black characters on a yellow background on the rear plate
- Not have a background pattern
- Not have an altered font or spacing
- Not make your car seem younger than it is
If at any time you display incorrect plates, you will be fined up to £1,000 and your car will fail its MOT.
Studded tyres
Studded tyres were first invented in Scandinavia during the 1950s to help drivers navigate through snow-covered roads with more grip.
Now they are part of a growing trend of car modifications.
But before you fork out on four new studded tires, please note they are illegal in the UK for everyday driving.
This is because they can cause damage to the road surface, however, they can legally be used in some off-road situations, including when navigating country roads, farms, and dirt tracks.
Therefore, if you don’t live in the country, making this modification could land you in trouble with the law.
It’s worth noting that not all insurers will issue policies for modified cars, even when they meet all the legal restrictions.
And while other insurance companies may insure you, they are likely to set very high premiums.