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How will modifications affect my car insurance?

How will modifications affect my car insurance?

Modifications, no matter how minor, could affect the cost of your car insurance. Whether performance-enhancing or simply cosmetic, your insurance provider will want to know if you’re making changes to your car. But the good news is that not all modifications will cause your premiums to increase.

Daniel Hutson
From the Motor team
minute read
posted 6 NOVEMBER 2019

What counts as a modification?

A modification is any change you make to your car that alters it from the manufacturer’s standard settings. Modifications tend to fall into two categories: performance or cosmetic.  

Altering your suspension, changing the wheels or upgrading your exhaust are all examples of modifications that might improve your car’s performance. Go-faster stripes, speaker systems and sat navs are cosmetic changes.  

Men are just a shade ahead of women in modifying and personalising their vehicles in 2019. At Compare the Market, we found only 33.67% of quotes that specified the car had been modified were completed by women.*

*Based on Compare the Market data from 1 July 2019 to 1 October 2019. These averages are based on all our customer quotes, from people with different age ranges, addresses and driving histories. You may find a cheaper or more expensive quote based on your circumstances.

What are the most popular car modifications?

We’ve pulled together some data that highlights the top 10 most popular modifications as disclosed and quoted from our site. You can read through our top 10 below to find out more:

  • Engine – changing the engine’s performance can dramatically increase the speed of a vehicle and make it practically a different car in the eyes of an insurance provider.
  • Wheels – adding bigger wheels and shiny alloys can affect handling and make your car a target for thieves. Try to use the vehicle manufacturer’s approved tyres when they need replacing.
  • Sat nav – unless fitted in the car, driver aids such as sat nav could be seen as risky in the eyes of insurance providers as opportunistic thieves might try to steal them. 
  • Tinted windows – as long as they’re the right side of the legal limits, changing the windows shouldn’t impact too highly on your insurance. The added privacy may even be seen as a crime deterrent by some insurance providers.
  • Alarms and immobilisers – some modifications could help to reduce your premium. Improving a vehicle’s security is a surefire way of getting in the good books of your insurance provider.
  • Stickers – even a sticker could be classed as a modification. A reverend in Wales was warned by her insurance provider that the religious messages she stuck to her car could invalidate her insurance policy. 
  • Bodywork – adding anything expensive to a vehicle increases its value and will need to be declared as soon as it’s been installed. Changing the body of the car can affect its aerodynamics and safety in the event of an accident.
  • Spoilers – a good spoiler will improve handling when travelling at high speeds. But it also increases the chances of speeding. If you do fit a new spoiler, ensure it doesn’t block the view from the rear window and is fitted securely by a qualified mechanic. 
  • Parking sensors – these are designed to reduce the risk of minor bumps, which account for the vast majority of claims. This type of modification could help you be seen as a safety-first driver. 
  • Exhaust – changing the exhaust system could enhance the performance of the car. Any changes to the original performance can affect the speed of your car and insurance providers see this as a risk.

Some cars may also be modified to make them easier to use for drivers with disabilities, such as wheelchair ramps and lifts, altered foot pedals, hand controls and steering aids.

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What cars are most frequently modified?

You probably won’t be surprised to find out that some cars lend themselves better to modifications than others. While there’s always likely to be fewer modified versions of these models than the originals, it’s interesting to see what cars have turned up in our top 10^^:

Model Sum of Enquiries 
Ford Fiesta 464
Vauxhall Corsa 220
Ford Focus 333
Vauxhall Astra 224
Volkswagen Golf 378
Mini Cooper 201
Volkswagen Polo 143
Ford Fiesta Zetec 114
Audi A3 157
Renault Clio 104

^^Based on Compare the Market data from 1 July 2019 to 1 October 2019. These averages are based on all our customer quotes, from people with different age ranges, addresses and driving histories. You may find a cheaper or more expensive quote based on your circumstances.

Why does it cost more to insure a modified car?

To understand how much more it might cost to insure modified cars compared with those that haven't been altered, we looked at our own stats. The average top 5 premium with a clickthrough for cars with no modifications is £714.04, and for those with modifications it’s £720.15.**. Obviously, depending on your driving history and the modifications you choose it may well be much higher – or lower - for you.

The cost of your insurance premium is based on the probability of you making a claim. So, when it comes to modifications, insurance providers will consider the following factors:

  • If the modifications increase the value of your car, then the insurance claims you make could be higher as it’s often more expensive to repair or replace parts.
  • If you’ve made your car faster, it could increase the risk of you being involved in a speed-related accident.
  • Your car may be at greater risk of theft, especially if you’ve had expensive tech installed, or you’ve modified its performance.
  • Insurance providers could also assume that any modifications that change the car from the manufacturer’s standard settings cannot be guaranteed and may affect the car’s integrity.
  • Young drivers are statistically more likely to claim on their insurance, so any modifications they make could raise their premium even more.

Don't forget, if you modify your car during the insurance term you need to notify your insurance provider about the change. This may alter the cost of the premium and you may also be charged an amendment or service fee too. Check with your provider before you start your modifications to see how it’s likely to affect your premium, so you have all the information you need to decide whether you want to go ahead.

**Based on Compare the Market data taken from 1 July 2019 to 1 October 2019.

What modifications could help lower my car insurance?

Not all modifications are considered a higher risk. In fact, there are some that could even help lower your premium:

  • Parking sensors – these can lower the risk of minor bumps and could reduce the cost of your premium by 13%.
  • Security measures – by fitting an industry-approved alarm, immobiliser or tracking device potential thieves could be discouraged. Tell your insurance provider if you’ve had any of these installed as they may offer a security discount on your premium.
  • Tow bar – if you use your car for towing a caravan, horse box or trailer you’re likely to drive more slowly and carefully, so a tow bar could lower your premium by 20%. But some insurers could potentially raise your premium as they might consider towing an additional risk, so it may be worth checking with your provider before you get a towbar attached.
  • Tinted windows – insurance providers’ opinions tend to be divided on tinted windows. Some consider them a cosmetic modification and could raise your premium. Others consider them a security measure as they can prevent opportunistic thieves from seeing what’s inside.

What if my new car comes with modifications?

If you’ve bought your new car from an authorised dealer and opted for some extra feature,s such as sat nav or alloy wheels, it shouldn’t affect your premium too much as they’ll have been fitted according to the manufacturer’s specifications.  

 However, if the modifications increase the value of your car, you may pay a slightly higher premium than you would for the basic model.  

If you're buying a secondhand vehicle that’s been modified, make sure you get all the details and pass them on to your insurance provider. The onus is on you to provide full details otherwise your insurance provider could potentially invalidate a claim. It's worth checking what comes as standard on a particular model so you know what might be different on the vehicle you’re buying.

Will I need specialist modified car insurance?

If you modify your car, it’s possible that you may need specialist modified car insurance. Cars fit into one of 50 insurance rating groups to help insurance providers work out a price to insure them. Any modifications to your car could mean it no longer conforms to its original insurance group and might invalidate a standard insurance policy. A specialist policy could cover you for even the smallest changes.  

A note from our experts…

Our Head of Motor, Dan Hutson says:

‘Modifications are always of interest to your insurance provider. While many small modifications are unlikely to affect your premium too heavily, it’s always a good idea to make sure you’re covered in the event of an accident. Although some of our data indicates that you could pay, on average, an extra 0.86%*** on your premium for a modification to your vehicle, this will depend on the type of modification you have. And there are many other factors that are considered when your premium is calculated, so be sure to disclose any modifications to your insurance provider.’

'While many small modifications are unlikely to affect your premium too heavily, it’s always best to make sure you’re covered in the event of an accident.'

***Based on Compare the Market data taken from 1 July 2019 to 1 October 2019.

How can I get a good deal on modified car insurance?

If you want to know how any particular modification will affect your insurance, then you should check directly with your insurance provider. And if you’re still keen on modifying your car, our comparison service allows you to declare any changes up front, so you know the price you’re offered will include any modification you’ve made.  

Compare car insurance quotes today and see what deals are available for modified cars.

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