I haven't driven it, but I have been taken around the circuit in the BMW 'Ring Taxi Program - M5 BMW's driven by professional test drivers who have clocked up hundreds of laps around the 'Ring. They strap you in and give you a fast lap - 8/10th's effort according to the BMW driver I went with.
http://www.nuerburgring.de/en/drives...ring-taxi.html
It is a FAST ride and very enjoyable. They also rent cars to take around the 'Ring on that website.