I had a long running saga with rust on a year 2000 Mercedes-Benz E320CDI. In July 2007 all four doors and the boot lid were repaired/replaced under the bodywork corrosion 30-year warranty. The boot lid rusted so badly that within six years there were holes in the bodywork. At the time of these repairs it was pointed out by the bodywork engineer that rust was appearing on the wings (wheel arch). Now the wings are in a bad way. Mercedes-Benz stated that a service by a non-Mercedes dealer invalidates the guarantee. I took Mercedes-Benz to the small claims track of the county court, won my case against Mercedes UK and was awarded a full settlement, costs and a contribution to my time. But it was small claims court and therefore no precedence in law.

The judge asked the lawyer from Mercedes-Benz HQ if the 30 year warranty was owner specific? He replied that the warranty transfers with the car. He confirmed that provided the car has been maintained from the fifth year by an 'authorised agent' then the warranty is valid for 30 years. The judge thought the requirement of this clause was hard to understand or justify on the basis that he could not see how changing the oil somehow caused the car to rust from inside.