Hello,
Well I have had my BMC CDA fitted for a couple of weeks now.......verdict........awesome. Well worth doing and a piece of cake to fit (I am no mechanic). Sound is great if you like that sort of thing (I do now). I am sure it is slightly more eager in the lower rev band but that may be psychological due to the enhanced great sounding engine note.
I have just attached a small length of pipe to the CDA unit and sits behind the headlight. Not too loud IMO but then again I am hard of hearing :wink:
Thought it polite to give an update......