These two 2007 satellite pics show what I am thinking of:

The possible circuit is within the yellow dashes. And the closeup below, showing part of the Nazi tribunes, is unmistakeably of a grid, a start-finish line, and pits with fresh tyre marks emerging from them. I'm not complaining, you undertstand, can't help thinking it's a far better use for the area, just curious because I've never heard of this circuit.
