<<J.HIDALGO There are some knowledgeable people there. I think it may be an aftermarket cable/connector to connect to an aftermarket cd changer such as Alpine. A lot better and cheaper than factory.>>

The factory radio in the C280 in question is made by Alpine as is the overpriced MB labelled CD player your dealer wants such a stratospheric price for. The very same Alpine CD player minus the all mighty star will cost less than $300 from various sources. You will need an adaptor which used to be available from Good Guys but that's a few years ago. I did all this to my '95 C280 in 1995. The cable is hidden behind the right side trunk lining. the other end is behind the radio and may not be plugged in. I mounted mine to the underside of the first aid kit box, out of the way but easliy accessible.

Roger Ellingson/'01 C320