I see a whole bunch or window regulator replacements. If your window is struggling, check this out before replacing that expensive part. It might just be one of the brittle clips holding the wire to the glass. This fix takes some time and a 3¢ cable tie (although the cable ties CAN break).
http://www.skene.org/bmw/window/index.html
I've got about 120K miles on my 2004 330xi. So far, the major things have been:
front passenger side axle (the boot had cracked, grease had fallen out, and the car was wobbling roughly under acceleration!)
valve cover gasket
oil filter housing gasket
DISA valve (the flap had cracked off)
Tube Elbow (fixed an air-related CEL, and a high-pitched whistle)
some stupid vacuum tube (fixed another air-related CEL ***8212; 10¢ of hose to replace some cracked hose)
Fuel filter (remember to clamp the RETURN line!)
Spark plugs
power steering filter change and fluid change
brake rotors & pads (hint: autohausaz.com has free shipping on those heavy things)
belts & tensioners, including conversion to hydraulic tensioner.
To do soon:
new battery - I'm happy with the 8 years I got out of the original.
Cooling system overhaul (using Bav Auto's kit part no. "E46 COOL AUTO")
transmission filter replacement and fluid change
differential fluid change
VANOS line change (because I'm still leaking oil)
So how do I know when I need to change shocks, struts, and bushings? I know
nothing about those things.