I'll be there for the German GP in July. Will be then spending the Sunday, Monday and Tuesday nights after the GP at the Nordschleife. We've booked a hotel that overlooks the old track (think you can see it in GT5 but need to confirm).
Currently looking at what race car rentals are available but beware the insurance excess's. Even a Clio RS is a 5000euro excess but a couple of companies do Suzuki Swifts with R-specs etc that are more affordable.

Try this website if you havent seen it yet: http://nurburgring.org.uk/