A car that has a removable top is called a convertible. More often than not, these cars are sport cars.
This hump was the drive shaft arc as cars back then were all front engined rear wheel drive vehicles.
Backseat - album - was created in 1986.
Think a bit harder, what do your friends call their open cars?
Backseat - song - was created on 2011-02-15.
Backseat Baby was created on 2005-11-30.
Backseat Betty was created on 2009-11-13.
This could be, 'Riding in Cars With Boys', starring Drew Barrymore.
The middle of the backseat; away from the windows.
Backseat of a Greyhound Bus was created on 2003-02-24.
An F150 has a pretty big backseat.
I have a 1996 Jaguar XJS Convertible. It has a small backseat suitable for children.