Off the top of my head (and probably omitting some important items):
Generally:
- regular diff and manual trans fluid changes (30k)
- regular oil changes with BMW oil or equivalent (I prefer 7.5 k intervals - you may differ)
- records of everything
- should have all new belts
- should have just had an inspection with new spark plugs, fuel filter
ZHP Stuff:
- rear shock mounts (and shocks - front as well)
- front control arm bushings, rear trailing arm bushings
- cooling system (radiator, water pump, hoses, stat, stat housing, etc... mine crapped out on my 323i at 140k, general consensus is preventative is good)
- lower intake boot
- power steering hose
Other stuff:
- does it have the 4.5k rpm "dip?"
- does it have the ZHP rattle?
- have the VANOS seals been replaced?
- has the tail light recall been addressed?
- have the o2 sensors been replaced? (doubtful, but why not ask?)
I'm sure our friends here will add to this list all of the items I missed. Cars with all of this stuff addressed are out there - at 118k miles, my car will be such a car! Though it's not your perfect color.