These are kind of interesting, though I'm leery of the German ones and the increased cost of insuring / maintaining them. The BMW is kind of neat, but would you feel funny buying from a private seller?
2003 BMW 330ci, $5000, 112k (dude selling it on Craig's List)
I would only buy from a private seller, preferably one who knows what he's doing maintenance wise. That said, I've owned a 2003 330i (sedan) from 103k to its current 167k miles and all said and done, it's been a bit of a pain in the ass. I do my own work on cars for the most part so it hasn't been particularly expensive (parts aren't bad) but here are the items that have failed and left the car undriveable over the past ~5 years:
power steering pump (okay, could drive it if you're the hulk)
camshaft sensor (no start)
fuel pump (stalls, no start)
leaky water pump (can start and drive but need to add water/coolant every time until fixed)
thermostat (same deal, slower leak though)
The car is currently my beater badly in need of a suspension replacement, burns oil, one window and sunroof don't work, covered in dents, etc. I'm driving it until it dies or until I move out of the greater Boston area, whichever is sooner (hopefully moving).
All this said, I like the chassis and design enough that I have another E46, but it's an M3 coupe with low miles and only occasionally driven, not a daily. I like working on nice cars so don't mind the maintenance, but I'd only suggest it if you are similar in that regard. The M3 has never been to an actual shop since it's not a daily and I can take my time with maintenance, time it well, etc. but the few times I've had to take the 330 in for something due to my own lack of time it's been robbery cost wise.