Was out with friends at the Tate Modern (modern art gallery in London) last year and finally got some pics of this. It's an exhibit called The Pack created in 1969 by a German artist called Joseph Beuys. It's a genuine Type 2 he used to drive around in and looked that beaten-up (i.e. it wasn't done as part of the art work) when it was on the road. No doubt it would be great to turn up at a car show (with the sleds in tow...) looking exactly as it does now, but apparently it's worth more as an exhibit than it would be if you bunged it on eBay. A lot more, apparently.
In 1940, the story goes, 19-year-old Joseph Beuys volunteered for the Luftwaffe. Three years later, while on a mission, his plane crashed on the Crimean Front, instantly killing the pilot. Beuys survived. According to Beuys, he only survived because some Tartars found him unconscious in the snow and took him back to their tents to care for him. They covered his body in fat and wrapped him in felt to keep him warm. As he regained consciousness the pungent smell of the fat and the felt appeared to awaken his inner artist. That's how he told it anyway. The truth was probably a little more prosaic; he was rescued by a German commando and taken to military hospital where there was no fat, no felt and in all likelihood, no Tartars.
It's on long-term loan from a gallery in Germany and been at Tate Modern since it opened in 2000.
More here, photos from (probably 1971) here.