One problem related to wiring has been reported for the 2002 Mercedes Benz C320. The most recently reported issues are listed below.
The light bulbs in my 2002 mercedes C320 are repeatedly going out. In the last year I have replaced (or had the dealer replace) the trunk light twice, the license plate light twice, both brake lights in the back at least once. In the last 3 months, we've replaced the front left turn signal light 3 times. The dealer cleaned the connectors last week - says that mercedes knows of a faulty electrical connector problem and an exec at mercedes was fired over the bad contractor they used. Currently the front left turn signal works sporadically. We'll bring it in to get replaced and it will work, so I drive it home and it stops working again. Now the dealer says I may need to replace the warning software (big $). He suggested I write to you.