Wikipedia
Atomette
The Atomette was a British three-wheeled cyclecar manufactured by Allan Thomas in Cleveland Street, Wolverhampton in 1922.
The car was powered by an air-cooled 3.5 hp Villiers two-stroke engine driving the single rear wheel through a three-speed gearbox. The body had no pretence of having a radiator and seated two people side by side. The car was advertised for sale at 90 guineas (£94.50) and could be ordered in a choice of blue, grey or green.