How do you top the longest racing circuit in the world? You go back in time to when it was even longer. ^^
More specifically, do we want:
(A) The Nurburgring as it was before ~1967? Remember, the removal of the Sudschleife wasn't the only change. The track has been made wider and smoother in some places, plants have been cut back (I think), and some corners like Hohenrain and Karussell have been added, removed or modified quite a bit. Plus, background scenery would have to look a bit older.
or
(B) A "modern" Nurburgring which includes the Sudschleife and Betonschleife? You could interpret it as a "what if" scenario. That is, "what if the original Nurburgring's Sudschleife and Betonschleife had never been abandoned?" This option seems a little easier since the Nordschleife wouldn't need a major redesign.
Layouts:
-Gesamtstrecke (combined circuit)
-Nordschleife + Betonschleife
-Sudschleife + Betonschleife
-Nordschleife only (to bypass the Betonschleife, you'd have to run part of it backwards and go through some sharp-looking hairpins...)
-Sudschleife only (goes via StichstraBe)
-Betonschleife (maybe not that interesting...)
-Karussel-Steilstrecke short circuit ? (goes forward through Karussell, and down Steilstrecke for a very short circuit.)