What difference do modifications make to car insurance?

In this piece, we explain why modified cost more to insure, which modifications add to that cost and how you can reduce the cost of insurance. In the eyes of insurers, modified cars don't just cover boy racers, but off-roaders, grey imports and classics. 

The number one modification is something you may have on your car...

Modifying your car is a huge no-no for most drivers, but there are changes that count as modifications you may not realise. Any alteration to your vehicle should be declared to your insurer and in many cases they will make no difference to the premium.

There are changes that will increase how much you pay, however. Anything that increases performance, the risk of it being stolen or the chances of it being in a collision will all push up the price. That doesn’t mean you have to abandon any hope of getting cover at a reasonable cost as there are specialist insurers who understand modified cars, whether it’s a high performance sports car, off-roaders, a classic or kit car.

As with all vehicle insurance, the key to getting a good deal is to be scrupulously honest when describing the changes you have planned. If you’re not, the worst case is you could find yourself uninsured and your insurer refusing to cover the cost of damage to your vehicle and any others involved an incident.

Men are twice as likely to modify their car than women and those aged between 21- and 50-years old are the keenest on altering their pride and joy in some way.

Number one modification

By far and away the most common change to cars in the UK is swapping to a new set of alloy wheels. This might sound like we are a nation of boy racers, but there are a variety of reasons for this. Yes, some drivers like to change to sportier wheels for the style they offer, but this trend has also been driven by many car owners now alternating between summer and winter tyres. That means many now have two sets of wheels and they have wisely told their insurer.

Another reason alloy wheels is the runaway winner when it comes to modifying our cars is the poor state of the UK’s roads. Potholes and broken tarmac are bad news for alloy wheels, which tend to crack and break rather than bend like a steel wheel. When an alloy is damaged, it’s often easier to fit a completely new wheel and if an exact match isn’t available it makes sense to tell your insurer of the change.

Other popular modifications

However, alloy wheels are not the leading modification in certain parts of the country, such as Yorkshire, Wales and the North West. In these areas, a tow bar is the most popular modification, which is unsurprising given their rural nature that means there are plenty of horse boxes and trailers being hitched up. This also explains why 4x4 brands such as SsangYong, Land Rover, Jeep and Mitsubishi all rank highly in the Top 10 of modified cars.

After these changes, modifications become even more regional. In London, drivers are more interested in parking sensors and tinted windows. Head into more rural parts of England and Wales and suspension alterations are popular. Some of this is fast car fans making their cars more suitable for the race track or rally stage, as we can tell from Subaru topping the modified car stakes. However, there are plenty of others improving their 4x4s for off-road driving. 

Top 10 most popular modifications
Alloy Wheels
Tow Bar
Parking Sensors
Tinted Windows
Suspension Changes
Exhaust System Changes
Chipped/engine Management System
Air Filter
LPG Conversion

Drivers interested in performance, whether it’s on-road or off, also account for why so many are keen to change their car’s suspension, exhaust and engine. This is to improve performance, either for outright speed or to allow a 4x4 to drive through deep water.

SUVs are also responsible for LPG (liquid petroleum gas) featuring in the Top 10 of modifications. Fuel-hungry 4x4s can run on LPG alongside petrol and LPG costs around half that of a litre of unleaded.

Other modified cars

For keen drivers, a new set of wheels and perhaps some small changes to improve engine performance are usually enough. Others will go considerably further, but they are a much rarer breed than you might think. Going to the bother of stripping out a car to make it lighter and adding a roll bar is an expensive business, so it’s mostly the preserve of those taking part in motorsport. It crops up in insurance data because some motorsport, such as rallying, demands the car is road legal.

At a very different point on the spectrum are cars modified to make them easier to control for drivers with disabilities. This can include wheelchair lifts and ramps, altered foot pedals and steering assistance.

Lastly, there are grey imports, which many insurers view as modified cars even if they are exactly as they left the factory. The reason is these cars were never officially sold in the UK and that puts them in the same category as modified cars. A typical grey import car will come from Japan, such as the Eunos Roadster or Nissan Skyline.

See also:  Our guide to Cheap Car Insurance for all car owners

Performance cars with the most reported modifications

These are the manufacturers of cars where owners conduct modifications. The percentage is owners that have declared a modification.

Manufacturer	Percentage
Noble	23.1%	What difference does it make to your car insurance?*
Lotus	16.7%	What difference does it make to your car insurance?*
Subaru	14.6%	What difference does it make to your car insurance?*
TVR	12.3%	What difference does it make to your car insurance?*
Lamborghini	4.6%	What difference does it make to your car insurance?*
Porsche	4.2%	What difference does it make to your car insurance?*
Maserati	2.6%	What difference does it make to your car insurance?*
Ferrari	1.9%	What difference does it make to your car insurance?*
Aston Martin	1.8%	What difference does it make to your car insurance?*
Jaguar	1.7%	What difference does it make to your car insurance?*

Off-roaders with a reported modification

These are the off roaders and 4x4s with modifications - typically things like tow bars and LPG conversions.

Manufacturer	Percentage
Ssangyong	6.6%	What difference does it make to your car insurance?*
Jeep	5.8%	What difference does it make to your car insurance?*
Mitsubishi	4.9%	What difference does it make to your car insurance?*
Lada	3.6%	What difference does it make to your car insurance?*

Classic Cars with a reported modification

Below are the classic car marques with the percentage of cars that report a modification of some kind.

Manufacturer	Percentage
Hillman	40.7%	What difference does it make to your car insurance?*
Datsun	34.4%	What difference does it make to your car insurance?*
Lancia	33.3%	What difference does it make to your car insurance?*
Riley	26.7%	What difference does it make to your car insurance?*
Austin	25.9%	What difference does it make to your car insurance?*
Standard	22.2%	What difference does it make to your car insurance?*
Sunbeam	21.4%	What difference does it make to your car insurance?*
Morris	18.2%	What difference does it make to your car insurance?*
Lotus	16.7%	What difference does it make to your car insurance?*
Delorean	16.7%	What difference does it make to your car insurance?*

Grey imported cars with a reported modification 

Below are the grey imports with the percentage of cars that report a modification of some kind.

Manufacturer	Percentage
Ford (USA)	32.8%	What difference does it make to your car insurance?*
Subaru	14.6%	What difference does it make to your car insurance?*
Isuzu	5.8%	What difference does it make to your car insurance?*
Lincoln	5.3%	What difference does it make to your car insurance?*
Cadillac	5.2%	What difference does it make to your car insurance?*
Mazda	3.7%	What difference does it make to your car insurance?*
Chrysler	2.5%	What difference does it make to your car insurance?*
Dodge	2.3%	What difference does it make to your car insurance?*
Hummer	2.3%	What difference does it make to your car insurance?*
Chevrolet	1.1%	What difference does it make to your car insurance?*

Top 3 Modifications by Area

Below are the top three modifications to be made by car owners in each area. Tow bars and alloy wheels are the most frequent modifications.

Yorkshire and the Humber
Tow Bar
Alloy Wheels
Tinted Windows
	Will this affect your car insurance?*
Wales
Tow Bar
Alloy Wheels
Suspension Changes
	Will this affect your car insurance?*
Scotland
Alloy Wheels
Tow Bar
Tinted Windows
	Will this affect your car insurance?*
North West
Tow Bar
Alloy Wheels
Suspension Changes
	Will this affect your car insurance?*
North East
Alloy Wheels
Tow Bar
Parking Sensors
	Will this affect your car insurance?*
London
Alloy Wheels
Parking Sensors
Tinted Windows
	Will this affect your car insurance?*
East Midlands
Alloy Wheels
Tow Bar
Tinted Windows
	Will this affect your car insurance?*
East
Alloy Wheels
Tow Bar
Suspension Changes
	Will this affect your car insurance?*

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