A friend of mine had a 535i that we bought to go to the 'ring in for a laugh. Was a nice barge but the 3.5 engine was a bit rubbish.
The auto box started playing up while we were out there so he got rid of it. It had been leaking so I think it had probably been run low and damaged it.
I have been thinking about a cheap touring as a tow car. Still have a soft spot for the M5, a car I would like to own.