man signing car insurance contract

Minor car modifications you never knew could affect insurance

We all know that kitting your car out with huge wheels, lowered suspension and a turbocharged engine will push up insurance costs.

But did you know that even minor and common car modifications can affect your premiums? Insurance companies calculate prices on perceived risk, and any modifications can increase, or decrease, your risk score.

Insurance companies consider three main risk factors:

  1. If the modification will raise the risk of theft by making the car more attractive to thieves
  2. If it will raise the risk of an accident occurring, such as additional power
  3. If the modification will raise the value of the car by being expensive to repair or replace

Car modifications means any changes or additions made since the car left the factory. This doesn’t include manufacturer options that are factory-fitted.

Here are some minor car modifications that can push your insurance premiums up or down.

Alloy wheels

Standard alloy wheels won’t impact insurance, but if you upgrade them or even paint them a different colour, your premiums could rise. This is because better alloys may increase the likelihood of your wheels being stolen, which is a common insurance claim.

Car seats

Modifications to interior upholstery can include upgrading to sports or leather seats. And these changes may need to be declared to your insurer, though it will vary whether they affect premiums.

Roof rack

Research from Moneysupermarket found that adding a roof rack to your car counts as a modification, and even pushes up insurance prices by 8% on average. 

alloy wheels car modifications that affect insurance

Parking sensors

Adding parking sensors to a used car is actually a good way to drop your insurance premiums. Moneysupermarket’s data shows that installing parking sensors decrease your insurance price by an average of 13%.

Tow bar

A tow bar is another modification that may lower your insurance costs. It can cut your premiums by 20% as it signals that the car would be travelling at slower speeds.

Tinted windows

Tinted windows are a risky modification because they must let in at least 70% of light to be legal, otherwise they restrict your vision too much. But botched installations and DIY jobs increase the likelihood of too-dark tints. And some insurers won’t even cover a car with this modification, while others bump up prices.

car park parking sensors drop insurance prices

Air conditioning

Adding an air conditioning system can add a high 13% to your insurance premiums on average.

Car decals

This is a grey area for car insurance. Some insurers don’t care about decorative modifications, but others suggest that decals like vinyl wraps and go-faster stripes raise the risk.

A small ‘baby on board’ sticker shouldn’t be a problem, but inform your insurer about anything else. A few years ago, one insurance company tried to declare a policy invalid after finding out the car owner had stuck messages across the side panels.

And if your decals or vinyl wraps are promoting your business, make sure your car insurance covers you for commercial purposes too.

air conditioning increases car insurance prices

Declaring car modifications

You must declare any moderations to your insurance company, whether they were made by you or already present when you bought the car. Sometimes modifications don’t affect the price but need to be detailed on your policy regardless.

If you don’t declare all modifications to your insurer and later need to make a claim, your policy could be declared invalid. The insurer may refuse to pay out or give you a reduced rate.

And if the cost of modifications is too high, shop around for a different insurance company – they all have a different way to calculate risk.

Thinking of buying a car? Here’s our helpful checklist of what to look for.