In the (okay, small) world of prototype cars built by aircraft companies, the Beechcraft Plainsman of 1946 stands out, both as the one that came nearest to production (notwithstanding the Highway Aircraft Corp. of the late 1960s) and the one that projected a hybrid gasoline/electric drivetrain and all-wheel drive. Beech engineers even figured out a way to display fuel mileage dynamically, but the best projections for mileage - due to the inefficiency of the electric motors - only his about 30 mpg. Short three-pager, but worth it.
The Jalopy Journal
