Pure speculation: Chineese Bubble-cars
In the late 70'ies and early 80'ies, small 2-stroke bubble-cars were all the rage in Chineese motorsports.
These small monsters were raced in spectacular hill climbs on bendy mountain roads. They were mostly 2-person cars with 1 or 2 cylinder 2-stroke engines, 1000 cc max. We're talking serious noise and "blue smoke" levels!!
Affordable, fixable and seriously poor handling. Good fun for spectators!