A bar dont sound bad, until you hit a pedestrian and the ins co say tough titty to you.
If they see the induction kit then you could be screwed.
Black wheels could be seen as more desireable, ie you have made the car a higher theft risk
A lot will depoend on the type of accident, ie fender bender no one really cares, but get into serious car write off or casualties and then its quesiton time.
Of course if you dont have anyhting it might not matter, but as you age and gain assetts then you have to be more careful.
My series and 90 are both pretty much std, but both have winches which are declared, no difference to the premium, but they did ask were they to be used commerically!