19. BMW Z1
Before roadsters like the Z3, Z4, and limited production Z8, BMW introduced the strange-looking Z1. The Z1 was a sleek roadster with uncharacteristic styling. The biggest feature was the plastic body panels and unusual sliding doors that disappeared in the rocker panels when drivers opened them.

Technically, you could drive the BMW Z1 with the doors down. The other interesting feature was the plastic body panels they bolted onto the chassis. Better yet, Z1 owners could buy different color panels and attach them to the car at their will. And that means you could change the paint of your car just by adding different colored doors and fenders, as well as the trunk and hood.