When I had my eclipse long time ago, I was also interested of being sponsored and did some research. There is no company that will hand out free shit. When they fully sponsor you, the sponsor "own's" the car and you are expected to be at every car show! It's almost like a full time job. But then that becomes you being an employ of that company
so instead of paying you cash, they will pay you in car parts for a vehicle that they own part of lol