Hi All We bought our S203 (2003 C220 Estate) in June and love the thing. But stupidly didn't check the rear seats folded when buying it (private seller). We did so many other checks but never even crossed my mind! The double - passenger side - rear seats would not fold down, the red button bit was popped out although the seats were locked firm! I've looked up loads of "walk-throughs" for fixing this problem - mostly on the E class but none of them helped me particularly as you had to attack the problem from the boot and the "parcel-shelf" bit was in the way! I'd talked to my indie who didn't want to touch it and the local merc dealer who was more than happy to do the job at some crazy price! I ended up attacking it on New Years Day - it was either going to be a Happy New Year or a rubbish start! I ended up attacking it from the side and pulled off the very side bit of cushion - you should be able to see this in the photos. From there I was able to release the upholstery from the side of the seat and reveal the broken mechanism! It took a bit of prying with a scredriver but I was able to release the rear seats by manipulating the mechanism! There were bent bits of metal in the mechanism and it basically wouldn't work! I phoned my next nearest MB dealership (Beckenham, Bromley) and spoke to a great guy called Simon in Parts and using schematics he found the part I needed! Ordered and paid for £54! Arrived yesterday and I fitted it and put everything back to rights within a few minutes just now! I'd be more than happy to talk anyone else through this if needed as it seems a reasonably common issue! Very satisfying to solve!