A new investigation has found that making the smallest modification to a car – even such as adding a sticker of your football team you support or performance badges – will increase your premiums and could invalidate your insurance if you fail to declare it to your provider.
The study identified which additions to a vehicle would increase motor insurance premiums most, from changing the wheels to significant performance upgrades.
And it also highlights the modifications that are likely to have little to no impact on the amount you pay for cover.
Auto Express used the example of a Ford Focus ST Line (pictured) to show what impact modifications could have on insurance premiums
Standard car: £467
Aftermarket alloys: £490 (+4.93%)
Increased performance badging: £504 (+7.92%)
Uprated brakes: £510 (9.21%)
Aftermarket sat-nav: £518 (+10.92%)
Decals/stickers: £541 (+15.95%)
Chipped engine management (ECU): £553 (+18.42%)
Upgraded suspension: £553 (+18.42%)
Roof spoiler: £554 (+18.63%)
Nitrous oxide (NOS) kit: £1,296 (+177.52%)
Additional turbocharger: £1,296 (+177.52%)
Source: Auto Express using a Ford Focus ST Line owned by a 37-year-old male living in Hampshire
Adding aftermarket alloy wheels saw motor insurance quotes rise by almost five per cent while fitting performance badges – such as Ford’s RS, BMW’s M-Sport or Mercedes’ AMG logos – would result in a near eight per cent jump in premiums.
At the higher end of the spectrum, the declaration of a the car having an extra turbocharger installed or the engine modified to run nitrous oxide saw quotes soar by nearly 178 per cent.
As well as informing insurers, motorists who have cars that are on personal contract purchase (PCP) deal also need to make their finance providers aware of any modifications as these impact the value of the vehicle.
With PCP monthly payments based on depreciation, the finance provider will want to know if you’ve made any changes that might make the motor less valuable when it’s time to hand it back.
Engine modifications to a vehicle on finance are expressly forbidden in the terms and conditions, especially if the parts used are not manufacturer approved components.
Earlier this year, This is Money reported that a YouTuber who had added a raft of performance upgrades to his BMW M4 had been informed he would need to purchase the £60,000-plus motor outright or have it repossessed as he had breached the terms of the finance agreement by making modifications that put increased stress on the drivetrain.
This not only invalidated the finance deal but also the manufacturer’s warranty on the machine.
Those who have cars on lease schemes are usually informed not to make any alterations to their vehicles whatsoever.