I firmly believe that the rust preventative/undercoating on a Benz is excellent. The rust on my MB is happening in different places for different reasons, but almost always from
moisture trapped against a surface, not salt. Plastic side panel mounting holes, rear quarter and floorpan rust from leaky rear window, spots behind plastic inner front fender panel, spots near front cowl where leaves blocked draining, road sand in jack points (probably aided by salt here), etc. In testament to the metallurgy of the affected metal, my rust is highly localized, unlike the huge sprawling blooms typical of domestic iron, such as my 80 Chevy pickup!
