Car Maintenance

Car Modifications & How They Affect Insurance

Finding out how car modifications can affect your car insurance is vital if you want to make sure everything is legal and safe. Whether you have been watching too many films or you spend a lot of time out and about, you’re bound to see some car modifications from time to time. They’re a really popular way of tinkering with your vehicle in what can be a relatively safe way, but a surprising number of common changes people make aren’t particularly safe, legal, or even easy to do, and that can cause a huge number of problems.

Even on top of all that, there can be further complications to car modification legalities too, and they often come from insurance policies. It can be really tricky to be able to do what you want in a way that’s safe, so whether you’re looking to do some modifications yourself or just expanding your knowledge, we have the info you need.

What are Car Modifications?

The best place to start with any explorative topic is by looking at the very definition of what we are going to talk about. What exactly are car modifications? The ones that are accessible to the general public at least…

Generally speaking, a car modification is any work that you do to your car that changes it from the stock state it was in as manufactured (minus replacements and repairs etc.) That covers everything from changing the bodywork all the way through to remapping, so it’s a big deal to make sure that you learn about what you’re getting into. It’s also worth noting that this can cover things like lighting and adjustments too, as well as the colour since this is used to identify your vehicle.

To help paint a clearer picture of the whole topic, it can be really useful to start by looking at some of the most popular vehicle modifications that there are to see their individual requirements and how they affect car insurance. Let’s take a look at some of the biggies:


Exhausts are often other first port of call for people changing their car parts as it’s fairly simple, cheap too, and doesn’t really have much impact on your vehicle in any way aside from the noise that it makes.

That in itself can be a big issue with the local authorities though if it’s too loud, so try to be considerate to some extent to make sure you’re able to keep any modifications that you make (or face a fine). There’s no real way to test this one though, so it can also be a good idea to think about how you are driving in residential areas and the longevity of your vehicle modifications.


Window tins are another cheap and easy way to add some edge to your vehicle, whether it’s for looks or for privacy, but that doesn’t mean that they are legal either. With this one, it all comes down to the specifics of the different areas of your vehicle to make sure that it is legal to use.

Legally, you can do whatever you like to the rear windscreen and the rear windows of your vehicle. You have free reign here. The front windows and windscreen, however, do have some strict restriction that you can be pulled over for at any time. Your front windshield has to allow 75% of light to pass through it, and the front windows have to allow 70%. This is for safety reasons and you will be forced to take these off.


One of the much larger, more expensive and more dramatically obvious insurance impacting car modifications you can make to your bodywork comes from the spoiler set up you create. There are tonnes of spoilers out there that you can fit to just about any car after all (even if you can’t really use them for their intended purpose in everyday life), but even these have some small restrictions.

You need to make sure that if a spoiler is something that you want to fit, that you can easily see anything you need to. Make sure it doesn’t obstruct your view and that it is fitted safely and correctly too. You don’t want this falling off.


Light changes are fairly straightforward and really don’t have much leeway at all. Your front lights have the be white, back has to be red, and they can’t be filtered as this will distort their colour and thus effectiveness.

Decorative lights like neon setups underneath are fine as long as they aren’t a risk to other drivers and the tubing is concealed safely. Flashing lights aren’t allowed though, so be careful with this too.


Another of the more complicated changes that you can make to your modified vehicle is the height of the car, and this effects car insurance too. It’s really popular to lower the suspension of your vehicle to have it much closer to the road (even if incredibly impractical).

Although this sounds like common sense, lowering your vehicle too much will actually make it dangerous to drive over bumps and speedbumps in particular. Although not illegal, it can cause a lot of damage and make it harder to justify with your insurance.


Remapping, although being a completely invisible modification, can still get you in hot water if you don’t take the proper precautions when getting things set up. In fact, this is about the only thing you need to know here really.

As long as you have not altered the integrity of the vehicle and you have paid the extra premium charge that increasing your vehicle’s performance will likely incur, you’re all good to go. Just make sure you do state it.


Because this has no impact on the safety or performance of your vehicle, there’s not much need to do anything about it if you want to change the colour. You do however need to make sure that you change the colour of your vehicle in all necessary places like your logbook/V5c.

Although probably not necessary, it’s always a great idea to speak to your insurance company about this one anyway as well as anyone else that has anything to do with your car. Technicalities really matter with things like insurance and with cars too, so change your details wherever you need to.

Car Modifications and Insurance Premiums

Almost all modifications that improve the value or performance of your car will result in insurance premiums going up (and a change in insurance group potentially). That’s because it usually means that your car is much more likely to have an accident or incur crime such as thefts and break-ins to retrieve the valuables inside it.

Some, however, do actually have the opposite effect, by making your car safer and less likely to have incidents. Things like cameras, sensors, tow bars, trackers and even advanced alarm systems can all mean that your insurance is much cheaper than it was at stock level. All of these protect you’re your car and make it less likely to need a pay-out from them, so again, it does make sense.

Whatever you do, make sure that you let your insurance company know, or your policy won’t be valid, and you won’t receive the help you need if something were to happen. If you’re unsure about the modifications of a vehicle, make sure you do a comprehensive check or speak to a professional who can tell you.

The same goes for fitting these modifications in the first place too. Always do any work you need to the highest standard and ensure legality at all times.

Happy driving!

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