hesitation, rough idle...help??

[BMWstep]

My 88 M3 has rough idle at start up and gets better as it warms up but still it isnt holding a solid idle.
car slightly hesitates through the whole rpm range, it almost feels like the clutch slip but it isnt. It seems like its getting worst everyday.
Anyone have any idea what it could be?

[Lanc3r]

A guess: O2 sensor.

I would normally spout off the "routine" items that afflict the aging E30s, but Dude! You have an M3! I would STRONGLY recommend a good Independent mechanic with M motor experience. IIRC there are 10,000 mile valve adjustment intervals with the M motors. This "could" be your problem. But, without some kind of history (parts replaced recently, last tune-up) its quite difficult to diagnose.