Go to the old Nurburgring. You can buy a pass and just ride right on off the street.
Some things in Europe are just amazing. Other things suck beyond belief.
From Wikipedia:
Nordschleife public access
The Nordschleife has remained a one-way public toll-road for nearly 80 years. At a slightly reduced length of 20.8 km (13 miles), bypassing the modern GP-Strecke, the Nordschleife is frequently closed off for testing purposes, training lessons or racing events. In the evenings and on Sundays, it is opened for the so-called "Touristenfahrten", i. e. to anyone with a road legal car or motorcycle, as well as tour buses, motorhomes or cars with trailers. This Nürburgring version is a popular attraction for many driving and riding enthusiasts from all over the world, partly because of its history and the considerable challenge it still provides. The lack of oncoming traffic and intersections sets it apart from regular roads, and the absence of a general speed limit, like on parts of the German Autobahn network, is an additional attraction mainly for foreigners. Accidents are common, though, and those considering driving around the Nordschleife should familiarize [1] themselves beforehand with rules that apply, as well as the "do's" and "dont's".
