Agreed. Recording inside the cab of an automobile is no bueno. I believe we covered home vocal recording a while back, however, I could not find it. The vocal cabinet should work OK. If you want to get great results you might try putting sound bat on the walls of a closet. Sound bat is expensive though and the equivelant of it is two layers of commercial R21 insulation, and one layer on top of non foil R19. Go to a construction site for these scrap pieces. Use gloves. Staple it to cover the walls and cieling and put a carpet down. I doubt they would hear you if you sang with a megaphone then!