Was my car illegally searched?

My fiancé got into a car accident. I got a phone call that he was going to jail for simple possession and paraphernalia that they found in the vehicle. They gave my fiancé every field sobriety test possible and he passed each one with flying colors. I pulled up to the scene to pick up my aunt's boyfriend. The cop came up to me and told me they found powder and asked which one of them does it. They eventually arrested my aunt's boyfriend on the charge without testing the substance. His truck was then towed while I was at the scene. I later found out that my fiancé never consented to a search. There was nothing in plain view. His car should have never been towed, therefore it should have never been searched. I need to find a Lawyer to help me out with this case the best they can to drop these charges.