Hi all, My beloved SL 500 (2002) has developed a loud rattle/scraping noise when the accelerator is depressed. Not exclusively then, as it also does it when 'freewheeling'. (54,000 miles on the clock - recently had full service. The noise is definitely NOT from the engine block. A Mercedes dealer diagnosed that a piece of the Cat material had broken away and was rattling around loose - as a result I had 2 after market Cats fitted and the noise seemed to stop for a few days. Now the noise is back - I'll describe it as best I can. It's like a piece of loose metal is either trailing the ground (I've checked and of course it's not) --- or like a small piece of metal or debris inside a drum rattling round....It most commonly occurs when gears are engaged, but also does it when standing idling in neutral. I'm in the middle of a grand tour of Europe and have a 1000 mile journey home in the next few days - and want to be reasonably confident it's not a terminal fault!! At least it might make it home to my local workshop! Can anyone suggest any possible causes? Thanks!