My first proper thread since joining, well, the first thing i did after purchasing my car was the dreaded swirl flaps!
Mine is the 330d sport model with the steptronic gearbox so i knew it would have them as apparently all the auto versions do in the E46 series.
Anyway, the procedure has been well documented by others here before, so i wont go into that again, except to say that mine were showing signs of age [eg, loose on the shafts etc so i am really glad i did them] however, i would just like to add that once you have the manifold off, its a good idea to check the condition of the number of small pipes that are under there, as mine were pretty shot, not leaking or broken as such' but very badly distorted and soft like chewing gum! I ended up replacing mine with new, and obviously disconnecting and plugging the outlet for the vacuum unit that used to operate the swirl flaps etc.
Anyway, i just thought i would mention this as their not the easiest to get to once the manifold has been replaced etc.