OK...update....

called the recovery guys which came in 45 minutes. they guy was supposed to see if he can get it going. He came and couldnt find the battery.

He tried to charge it using the + terminal and the body in the bonnet. It cause d some lights to come on but not enough power to start it.

I thought if its the alternator then he might aswell take it to the local squealer while he was here....So it was pulled onto the ramp and taken to the local bmw squealer ready for them to diagnose the problem in the morning.

Anyway the guy rolled it off the truck...before getting out he turned the key....and lo and behold it started it.

Any ideas anyone....? Why did it suddenly start again....?

Could it be a loose connection which ? Could it be the movement of the wheels which done something to the alternator?

My problem is that I don't know when this will happen again....