I know that seats are usually higher in trucks, SUVs, and vans, and that seats in sports cars are usually lower than those in regular cars. I tried to find seat height dimensions on the Internet but I couldn't find any. If a kitchen chair seat is 18" high, I think that seats in trucks, SUVs, and vans are as high as a kitchen chair seat, that seats in regular cars are about 12" to 16" high, and that seats in sports cars are about 6" to 9" high. Sitting in the rear seats of third-generation Chevy Camaro/Pontiac Firebird was like sitting on pillows on floor. I think that the rear seats in those cars were lower than the driveshaft tunnels. If I want to build a car, how can I find info that I need?