Hmm I thought i'd try the ASSIST route too yesterday.
Called them out he arrived 1hr later then expected.
Took a look at the car with his OBDC dianostic kit.
Found no fault - suprise suprise!
Had a chat to him about a few things like the MAF and what else could be causing the problem. He's suggested I let BMW have it for a week so that their specialist from Bracknell can check it over. He's also mentioned about having a loan 320si to compare with.??
He did mention about another 320si in my area which has had a coil pack failure. He also mentioned about some serious QC faults on lots of E9x cars.
From what he told me sounded like I'd got a car built by Italians! (i've had a pininfarina built car and a Fiat before) (Nothing against Italians - they build the sexiest cars - but don't build them well
I've just called my lease company as I need to keep them in the loop as they can apply some pressure on BMW. I'll see what the chap says when he calls me back. Keep you all posted