The second car I want to mention is a 1961 2CV Sahara. Citroën wanted to make a four wheel drive version of the car but, not wanting to get involved with transfer cases and the like, they saw another way to do it: they installed a second drivetrain in the rear of the car to drive the rear wheels. It was the exact same as the one in the front, just facing backwards.
The spare was relocated the top of the hood. The car now had two gas tanks and they were relocated to under the front seats, with the filler hose popping out of either front door. Few were ever sold and these are a rare sight today.