Nice pics. What are 22,000 cars doing there?
The site is home to Mannheim car auction who handle a lot of top end motors, Maserati,Porsche , Jag etc plus it is also a storage /pdi and refurbishment site for some of the big car hire firms, one of which I work for. When the cars finish their rental life they come back for refurb and then either go into dealer approved networks or sold through auction. As March is new registration time all the older vehicles come off fleet as the new ones go out hence the large amount sat there. Plus the manufactures can't shift them quick enough either. They did say this was the most they had ever had on site, as a rule they don't like to store vehicles on the grassed areas.Even at 600 acres they can run out of hardstanding.
Also the site has a race / test track, when I was there Bentley were setting up for a drivers day. A lot of TV companies use it to film on. Royal Enfield are building a new R+D center there and there is also a refurb center for heavy plant machinery.