That's awful. By trying to use that solution aren't they basically admitting that your current X5 has a manufacturing defect? Even if they did that how would you be covered by say problems this may cause with the transmission three or four years down the line. I would talk to the Society of Motor Manufacturers and Traders, a freind of mine had a problem with Audi recently....they absolutely wouldn't budge and he was looking at a £5000 bill. He got the SMMT involved and two weeks later Audi were collecting his car and doing the warranty work for free.

I would also tell them you want an X5 loan car. BMW GB must have a load of staff/press cars at their disposal right now. Tell them you want one.