I fitted mine meself then had the rattle - was a piece of cake - just had to angle grind the old one in half to remove.

Found the problem anyways - the decat pipe was sat a touch to near the front causing the flexipipe to just touch the drive shaft when it got hot - there's a seem weld around the pipe right at the level of the Drive shaft.

Anyway undid the two bolts holding the decat on and the top turbo joint and slid it back 1/4 inch and now perfect.

Thanks for your response tho.