What sort of offers have you been getting on ebay? Does your head in selling cars on that site!
M3's have dropped in value massively though, if you have a look at the completed listings on ebay they're not making much. Worries me about buying one, hate losing money on cars but it looks like the prices are going south.
As well, I reckon the fact that the SMG fault is known to happen usually around 60k which is what yours is could be putting people off.
What plate is the car on? 53, 04 or 54?