don't bother, buy my 330ci instead, i want an m3 now lol!
subframes!!!!
then inspection 2 is a must, good brakes as they are expensive to replace.
listen for vanos rattle, easy to fix yourself or costly at a dealer.
smg gearboxes can be expensive when they go wrong, but very good when they work.
manuals are rare, but weight saving and less expensive/prone to failure.

this is pretty much what i've found out so far, but the 330 would have to go first and flog the 206 we have sat on drive too, only driven a couple, but not the best condition so didn't part with my cash.
there are a lot of dogs out there at average prices, cheap ones so far have been shite, dear ones are just that.