For restraining Molson in the car, we have him wear a harness (just a simple one from Petsmart, $20) and an attachment that looks similar to a very short leash (maybe 12" long). It clips onto the harness on one end and on the seatbelt goes through the other end. It keeps him in the back seat and leaves him enough room to lie down, look out the window or turn around, but still keeps him restrained, comfortable and safe.