Thanks for replies: - GaryM the rattle is not there when the car comes to a halt, when at idle or when you switch the engine off. It only appears when at low revs either starting from a standing start, at the beginning of acceleration or when at low speeds and you need to accelerate. Strangely when you start it first thing in the morning and it is stone cold this noise isn't there at all in any of the above situations. Why i am concerned is that it only came with a 3 month warranty that ends on the 3rd December and I have had it back for a sqeaky roof already that is when i mentioned it to the dealership mechanic who seemed to pass it off (although when we went for a drive there was only light traffic on the road and we didn't really have to stop or start to much). He mentioned there was a slight rattle on what he said was the 1st turbo initiation but then said the car sounded fine when the 2nd turbo initiation kicked in - I left thinking it was all in my head. I just hope i haven't been sold a pup and in a short while i might get hit with a large repair bill cause i don't have the money. Just out of interest if the DMF went how much would that cost me? I also had a chat with a work colleague who was a mechanic a few years back although he did say the modern engines nowadays are alot more advanced than when he worked with them but when i explained the symptoms he said that it sounds like the car engine management system might not have the correct fuel settings in that the engine settings are correct for when the engine is cold (hense bring smooth with no noise) but are not set properly for when the engine starts to warm up. I don't know if that makes any sense. Anyway I think the only thing I can do is ask the dealership to run a diagnostic check although i dont hold much hope of them finding anything or at least admitting to finding anything.