Multi use Rims

I've got a set of steel rims (15") that came from my Audi A4 Quattro. Looking to sell them, however don't know what other cars they may fit. Any suggestions on where to find out?

they're 5x100, there's tons of cars that are 5 x100, but briefly, all 5-lug VW's, Audis, Subarus and Neons