I can tell you a couple things. The first is that a dealer can probably write (from his discretionary fund) any warrantee he likes. MB isn't buying it outright.
I can also tell you that no one that works for MB long talks much about what they cover beyond their stated warrantee. If they do they won't be doing it long. One might think about that before publicly asking such a question of an MB employee.
Bosch Master, ASE Master, L1
33 years MB technician