some 01's and 02's (i think) had rod bearing recalls. 03.5's and on were pretty much free of problems.
but they as all e46's were susceptible to torn rear subframes. you won't be able to tell if the fcabs or rtabs are shot by just looking at them. they are pretty much covered. if you feel the rear end really loose and unstable, the rtabs are shot. check the floor in the trunk for any cracks. those would be the first signs of a torn subframe. loud ticking means the valves need to be adjusted and could mean that the PO didn't take care of the car much.
good luck on your search.
Current:2013 Candy White VW Golf TDI
Sold:2004 Silver Gray M3
Mods: Dice Unit, EAS Angel Eyes, Painted Reflectors, CSL Diffuser, Smoked Corners, PSS10s, 15mm Front and 10mm Rear Spacers.
Gone:1990 Brilliantrot 325is
Mods: Alpine speakers and HU, Euro Projectors, Magnaflow Muffler, Euro Smoked Tails and GC Coilovers.