There isn't any bad year. If there is any concern at all about model years, it might be the 2001 models. Only because this year was the first year of the S54 engine and there were problems with bearings burning up. BMW has since offered a longer warranty for these engines. '99 and '00 models feature the proven S52 engine. It's pretty much bullet-proof and mighty powerful in its own right.
The subframe issue is just one you'll have to inspect or have inspected. It seems to be more prevelant in Coupes that are driven to the extreme. Like say a regularly tracked car.
The M Coupe has several little hiccups, but there is a remedy for all of them. Here are some common "problems": whacky gas gauge, wobbly seats, leaking rear-window wiper, notchy shifter and rattling glovebox.
My 2000 M Coupe is for sale if you are interested. I'm in Dallas. Let me know if you might be interested.
2000 M Coupe
Dinan strut brace