The Nürburgring GmbH and couple of other Companies are insolvent, they have around 500+ Mio. € debts, plus the owner of the Nürburgring (Automotive) GmbH are bankrupt (Lindner) and has a warrant on his desk (Richter), so things have looked a lot brighter at the Nürburgring, but I think/hope that this will solve out to not only save the track but also the infrastructure surrounding the Nürburgring.
Still, the Nordschleife is still open for Touristenfahrten, and manufactures still test their cars there. But we'll have to see, how things will progress in the future.
And companies like RentARacecar, Rent4Ring or OK Speed (BMW Ring Taxi) have nothing to do with it the Nürburgring (Automotive) GmbH what so ever!