Yeh i suppose it does, although the camera sounds slightly different. At the nwvag meet lastnight people we saying how it doesnt sound like a diesel but has a really deep bellow I couldnt imagine how loud it would be without the back box!
I always thought it had a middle box
I might give the garage who supplied/fitted it a ring to see, im not to fussed though. Looks like ive got a non-res then lol