Yeah I guess I would do a check to make sure they arent going to see them as performance upgrades and hike the price of the insurance up. Was just interested in other peoples experiences. Thanks!
@chux27 - be aware that non performance upgrades might also result in premium increases - it depends on the insurance company’s approach to risk and whether or not they consider the proposed modifications increase the insurance risk. There isn’t a standard market approach to modifications by the insurance industry, so where one insurance company may require an increased premium another insurance company may not. I’ve fitted non-OEM alloys to my three previous cars; on two occasions, the insurance company I was with didn’t increase my premium but on the third occasion there was a modest premium increase.
With non performance cosmetic modifications, some insurance companies might consider cosmetic upgrades would make a car more of a target for theft as it might be more visually appealing to certain types of
scumbags perpetrators who are looking for a ’free’ car

. Also, the addition of aftermarket bodywork such as side skirts, splitters and wing extenders can mean accident damage is more costly to repair - i.e. there’ll be additional costs involved in sourcing, painting and fitting the extra non-standard parts compared to the cost of repairing a standard factory spec car without cosmetic upgrades.
As
@tracktoy has said, always declare any modifications; pretty much all car insurance policies will have a clause in the small print requiring you to do so and not declaring them could result in your insurance company voiding your policy.