For voting purposes we need topics to be limited to one idea each - in the case of brand name car parts that means a single manufacturer for each topic.
If the suggestion is for revising a non-aftermarket part such as Forza designed bodykits for cars that are currently in the game, those suggestions should be posted in Car Modeling identified by one specific car model per topic.
See also generic customization suggestions in the Car Features section such as New Forza Aero across the car roster.