The noise I am referring to is a low rumbling rattle which appears to be coming from directly underneath the passenger footwell. It only happen under specific conditions - engine warm, going uphill, usually a rough road surface, engine under pressure as I am towing a caravan, around 3000 revs. I have checked the exhaust and it appear to be rock solid, just passed mot as well. Am I looking at a baffle which develops a resonance rattle? If so are my only options to (a) ignore it or (b) replace the exhaust part?  :y

My 2.6 sounded the same when the coil pack was starting to go causing a misfire under load :(

hope yours is different but worth checking :y

I hadn't considered a misfire mainly as the vibration felt through the floorpan is so significant, also there is no indication through power loss that it is a misfire, Worth considering, thanks for the suggestion.  :y

I have a 2.6 elite and have the same trouble except mine seems like its coming from the rear passenger side, exhaust is fine. happens when under load and going uphill at around 3k revs, also happens when travelling 85-90, im baffled but if you find out anything please let me know

Heat shield on the cat secure?  Try a large hoseclip (or series of hoseclips daisychained together) to secure it all to itself and see if it goes away.