British Car Auctions (BCA) has warned people to think carefully before changing the look and performance of their vehicle, as modifications not only attract higher car insurance premiums but can also lower its resale price.
Mismatched alloy wheels, fitting phone holder kits which damage the interior, tinting windows and lowering a car's suspension can all lower a vehicle's resale value, in some cases by as much as £500.
Tim Naylor, PR Manager of BCA, said: "That boy racer bling may be appealing now, but retro-fittings can put the average buyer off, so it may be better to go for something with universal appeal, such as a good in-car entertainment system.
"When it comes to customising vehicles, BCA's used car experts believe that less is definitely more for those who want to maintain the resale value of their vehicle."
He said that the majority of motorists are wary of upgrades that are retro-fitted, particularly on younger cars, where there are concerns that this might void any warranties.
Modifying a standard car reduces the potential audience of buyers, especially if the quality of upgrade is poor, he added.
© Press Association 2010