Back in the 80s a friend of my dad had a Wartburg Knight that was ahem - slightly tuned - he used it as a support car for a rallying and he was faster in it than some of the competitors, I still have the book he gave me 'Tuning racing 2-strokes' . He rode speedway in the 30's and had a few bad spills so he walked with quite an extreme limp which enabled him to get an Invacar invalid carriage - the blue three wheeler contrivence - he took out the wheezing Villiers 2-stroke and fitted a 500cc J.A.P engine from one of his speedway bikes - he got stopped doing 50mph in London (he lived near the Post Office tower) but didn't get prosecuted because the PC said no one would believe him if he called it in!
The Wartburg factory in Eisenacher, originally was owned by BMW, and pre WW2, built BMW cars there, after the War, the Soviet occupiers wanted to crate up the machinery & ship it back to Russia, however they were persuaded to leave the factory open, as long as they could build 5 cars in a week, the Soviets agreed and started shipping BMW cars & Motorbikes back to Russia, in 1952 BMW issued a lawsuit to stop them using their name, so the cars produced there became EMW's with a similar badge, but used red, instead of blue, the company later became known as VEB Automobilwerk Eisenach, and went on to manufacture the Wartburg models instead, so that rattling, coughing f*rting Wartburg isn't a BMW, it's BMW's East German cousin!