I have been so tempted by these for ages, the main thing to watch for is the cracking boot floor issue and pre 03 models had a engine bearing recall, along with making sure the "vanos" are ok, and if it's an SMG model make sure it works ok, and see if it's had the pump replaced, as they are big money to rectify when they go wrong, I would like a manual really, but it seems hard to find one with the right colour combination etc.
Also, as said, do the sums beforehand to make sure you can afford to run it, they are cheap to buy for a reason!
I am not a fan of modern cars, but this is one exception.
Martin