Mileage: 56,103
Installed a used M3 strut bar that I purchased from a guy over on E46Fanatics while I was still in DC. It's in great condition and even has all of the black caps for the longer nuts. Only noticeable damage to the strut bar is circular scratches caused by the four nuts on the bar itself, which I don't think is avoidable.
Install was straightforward enough. I just followed Madrussian's guide (
Link) and your guys' suggestion for order of nut installation (base plates first, then bar).
Obligatory crappy phone pic: