What could a rough idle mean once my car reaches temp?

 

Big cams!

 

This. My s2's are rough.

 

bad afr... weak ignition coil... weak injector... misfire... stuck valve... minor vacuum leak...

do you have a boost gauge? what are your idle vacuum readings?

you could try a power balance test... unbolt your coil packs... start the car... have a friend rev it up to 1500 or so... then one by one remove each coil and record how many rpms it drops...
the lowest drop indicates a weak cylinder...

you can also use injectors but with our retaining clips its harder to pull off...