If the timetable is the same next year,
Leaving on the Saturday you will only gain an extra
2 hours on "The Ring" by staying till the Thursday, because its only open on the Tuesday evening.
I would suggest nothing can be done untill the timetable is published in January 2012.
Here is this years timetable:
http://www.nuerburgring.de/en/angebo...dschleife.html