When I insured my car I decalred all mods that I intended to put on the car, even though some aren't on yet. I was told that if I stacked my car, the non standard wheels, and exhaust would be replaced with standard ones, but the body kit I intend to fit would not be replaced at all. I would have to cover the cost of that. However, because all mods have been declared if another party hit my car, all mods would be replaced with identical replacements. (including the body kit).
Any car that is fitted with optional extras, even at the factory, have to be declared. I do agree however that some peope may not know that their car was fitted with extras and may assume the car came like that, unfortunately though, it is the car owners responsibility to find out all they can about their car and declare everything to the best of their knowledge.
I do think it is abit of a grey area, especially when it comes to people who know nothing much about cars at all . My friend would be in a very dodgy situation if she picked up a car with added extras, she would not have a clue and would assume the car was meant to be like that as standard. This is where, in my opinion, insurance companies should have detials of all standard models of car and all their possible optional extras. They should then ask the customer if their car has any of the extras and go through the list of these with the customer. This may be a little time consuming as some peope may have to run out to their cars to check, but at least then the cars and customers would be correctly insured. I'm not quite sure how someone who knows nothing about cars could check if their car had sports suspenion though. :S
