MG Rover sold the Longbridge site to St Modwen about a year before they went under, in order to release funds. That is why the prospect of Saab doing the same thing with Trollhatten is somewhat ominous - they have already sold the rights to the old 9-3 and 9-5 to the Chinese, and I am not sure what the IP situation is with regard to the current 9-3, new 9-5 and 9-4X is. Are these owned by GM?
MG Rover were selling various assets to help keep the business going, and their cash flow was apparently horrendous - Saabs sounds very similar :-o
Interestingly enough, St Modwen seem to have been there ready to buy the land whenever a midlands car site was shut in recent years. I believe (not confirmed though) that they also got Browns Lane, and Peugeots Stoke and Ryton Plants too. Well after all, you can't have too many houses and empty light industrial units, eh? :-o
The Peugeot plant at Ryton is now just a massive open spave with a pile of bricks on it, the Peugeot Stoke plant has been bulldozed with a little bit rebuilt to house the training and parts operations, the rest is....houses and light industrial units........Longbridge has been largely demolished with the exception of the assembly end of the site which is leased to the Chinese, the rest has....errr.....light industrial units, and a new college is supposed to be going on, no doubt accompanied by the obligatory supermarket :-o