They're slow, unsafe, uncomfortable, cramped, catch fire easily and are terribly primitive. But they are also simple to maintain, very, very cheap to buy and run and have a bit of cult status.
When Communism strated to crumble in the DDR, followed soon by an ingress of East Germans to the free West, the image of that to Europeans will forever be Trabi's crossing the border from East to West the night the the Wall came down.