This was a North American 'street stock' series run in the mid to late 1980's. Ur quattros participated in this series in at least 1986 and maybe 1987. John Buffum drove one the cars as part of a 3-driver team. The results were not ever good ....
Nonetheless, cool to see the quattros in action in a non-rally series.
There was also a 24-hour race at MidOhio in either 1986 or 87. A friend of mine fielded an ur quattro loaned to his team by Jo Hoppen at Audi North America for Elliot Forbes Robinson and a couple of other drivers I don't recall. He's been trying to track down some photos for me without success. As I recall the story, they were under strict orders to leave the boost alone. EFR wasn't happy with the power and convinced the mechanics to turn up the wick a bit. He then proceeded to go out and blow-up the car. I think the car was then purchased and converted to street duty.