Running rough when cold

[Trevor]

Okay, it's not the old E34 (5yo E46), but pretty much similar set up.
A sweet ride, but as with all things BMW, there is always something to tweak/fix/improve.
When the engine is cold, it runs a little rough. Smoothens out once running temp is hit, and runs sweet.
Is it likely to be:
Plugs?
Dizzy?
Coil?
Rotor?
MAF?

Appreciate feedback before I do the old E34 routine and start replacing everything....

[Kalevera]

Probably a self-sealing air leak somewhere along the intake or a confused computer. Any engine you'd find in a US spec E46 won't be susceptible to rough idle vacuum leaks, but there's always a first.

best, whit