The Random E46/ZHP Question Thread
Take the belts off. Turn them inside out and squeeze like this:

If you see any cracks in the ribs. It needs to be replaced
While the belts are off, spin the tensioner and idler pulleys. They should spin relatively easy with no noise or roughness. If they need to be replaced you can replace just the pulleys. No need to replace the tensioners too
Here's a video of a bad pully in my car. You can see it wobble a bit.
Dinan CAI &Throttle body, ESS Tuning TS2, Bimmerbrakes gen3 headers, UUC SSK & DSSR. Achilles oil pump, VAC oil pan baffle
M3 Motor mounts, UUC Trans mounts, Modified clutch style LSD 3.15, TMS front subframe reinforcement, Koni Yellow sports,
H&R sport springs, UUC sway bars, BMW Perf. Rotors, UUC SS brake lines, Hawk HPS pads, CSL replica wheels,
Rotora strut bar, FXR HID conversion, M3 Mirror conversion, BSW stage 1 speakers