Some quick searching failed to turn up anything official from MB. I do know my car had both spring perches replaced at 5 and 7 years (an almost unheard of repair on other models at even 4x that age). One of those was covered by MB. It had both front fenders replaced, a quarter panel repair, and two outer rockers replaced, all out of pocket and all in the first 10 years. I ultimately scrapped the car rather than doing a full inner and outer rocker replacement to keep the car safe.
The next series (W211) changed the prep process to better galvanized panels and the rust problems returned to “the other cars of that age” level.
Googling “w210 rust” will give you plenty of forum and owner experiences, but nothing about the particulars of the water-based primer/finishing process.
