I have just been reading another car forum (not toyota) and the post I read was from a young guy who had modified his car. He has had an accident and is now worried because he did not inform his insurance company of his modifications and they are coming to inspect his car. When you insure your car and say "no modifications car is factory spec" it means your car is how it left the factory. If you change your alloys for steel wheels with winter tyres you have modified your car.