I don't know if this is intentional, but after replacing all parts with new pristine parts in a crashed car sometimes the car remains undrivable and ruined. This has happened in all 3 car types and usually the car has black smoke coming out of it. Even with all 4 wheels and all car parts pristine the engine will not start. Maybe add an icon saying "ruined car" or change it so that replacing all parts fixes the car and stops the smoke.