Originally Posted by Can't Know

You won't get that. The lamp malfunctions are all for external bulbs. The PCBs for the tail lamps can wear out and need a little cleanup with some additional solder and/or new lamp holders. The headlamp and foglamp wiring is marginal so you might have to replace that (there are repair kits available). The drivetrains are solid so long as they're properly maintained. The spring perches are an expensive repair, too, and the earlier ones were a bit worse about that. There are some quirky things that arise, but they are quite rare. The AC stuff is really costly to repair, condenser failures aren't common but they do happen and less frequently it's the evaporator core, which on a car of that vintage nearly totals it if you're paying dealer rates for labor. The W210 is nothing like the W220, and those bells and whistles are more prone to failure and they cost more to rectify.

If you trust the mechanic, read through the common issues list referenced above and then formulate some questions to ask the mechanic. Obviously if he didn't even look at some of the things that doesn't help you.