Aero 500

The original model, the Aero Type 500 cyclecar, had a 499 cc single-cylinder two-stroke engine with water cooling. Drive was to the rear axle through a 3 speed gearbox to a back axle without differential. Body styles were a roadster, cabriolet and coupé all with two seats in the front and one in the rear. About 1500 were made. (Wikipedia)