Just in case anyone was interested, I replaced the exhaust and CAT with a full GPR exhaust system. This made massive improvements to the strangled OEM sound but no noticeable performance improvements, even after Nelly at Cornerspeed remapped my Rexxer unit. I never really thought about the panniers until a mate of mine suggested a MAG rally at Helmsley in June. Fortunately, probably more through luck than design, or maybe the Italians took that into consideration, I can report that the panniers fit perfectly with the GPR exhaust.
