I think I’ve never have been in a 40’s car but I remember cars being tanks.
Probably got ten miles a gallon but I remember gas at 31 cents/gal
If you watch many movies from the 30s and 40s you can get an idea. If you were driving alone, you’d drive up to where you were going and leave the car using the passenger’s door. People getting into the back seat would bend down and kind of walk to the back seat. Today a back seat is roomy if your knees aren’t hitting the front seat.