TIL General Motors built a 61 Chev Impala with a flat / boxer type 10 cylinder engine and front wheel drive

This was built as a test/ prototype, and was an ancestor of the FWD 1966 Oldsmobile Toronado and 1967 Cadillac Eldorado. The engine was a prototype of a modular engine family that was intended to range from 2 to 12 cylinders, based on the Corvair flat 6. Only 2, 4, 6 and 10 cylinder engines were built before the project was abandoned