Bob
Euro Car Parts (
www.eurocarparts.co.uk) can supply centre sections with centre box for £43 and a rear silencer box section for £56.60.
Both made by Bosal... which is a good quality manufacturer from first hand experience on my old 5 Series.
Original equipment exhausts on the 2.2dCi Grand are made by Eberspächer... or at least they are on mine!!... but you don't seem to see them in the aftermarket for some reason.
Strange how your original exhaust has only lasted 32,000 miles. Mine is 5 years old and done 78,000 and looks like lasting another year or two yet.
Martin