I have some experience of the Mercedes Mobilo 30 year body warranty. In 2004 I bought privately a low mileage 1999 Mercedes S500 (W220), made in the dark days of MB quality control. It was silver, which was the main problem colour, and its paint basically fell off, along the door bottoms, front wings and boot lid. In my two years of ownership, the car was resprayed by MB three times and had a new boot lid.

There was no visible rust, except along the inside edge of the boot lid where the skin wraps under. Following the last repaint, needless to say I got rid. The point is, this car only had a 3-year body warranty. I think the Mobilo 30 year agreement didn't start until 2001 (I had a 320 SLK on a 51 plate which had the 30 year cover). Mercedes unofficially extended this 3 year period up to 8 years for cars with full MBSH. I was told this both by the body shop manager and also a friend in the trade who has a paint shop.

Mercedes were so inundated with this type of work they were farming jobs out to independents like my pal. From my personal experience MB Sheffield bent over backwards to rectify my problems, obviously with agreement from Mercedes. Pity they weren't making better quality cars around this time as the problems I had with the air suspension make another (very expensive) story!