Any performance upgrades from standard need to be declared as a 'material fact' or you will invalidate your policy. If there is a personal injury claim/ loss of earnings they will be knocking on your door. Just call and mention it to your insurer and broker and note when you did it, you may find it doesn't increase your premium. Fitting roll bars, different alloys and different size tyres are all material facts.
If you do have a claim, assessors will make a point of checking tyres on inspection, direct line seemed to be the first, they all do it now. Certain claims will mean they need to check service histories as well. So keep your records up to date.
Assessors are only doing their jobs, this also includes looking for potential fraud as well as looking at repair costs
