94 E320 Radio/speaker

[94 E320]

My front passenger door speaker quit working recently; just before it stopped working completely, it would "pop" and cut out ocassionally indiscriminate to the volume level setting. I pulled the door apart and observed, wiggled, and traced the wires for obvious damage but could find none; there is a module located inside the speaker box itself, which I could not open, to which the incoming wires run into and then out of to the speaker. I would like to remove the radio to inspect the wire connections on the back, hopefully without having to remove the center console. There is no insignia which indicate a manufacturer, only Mercedes-Benz on the cassette slot door. There are two thin slots directly to either side of the unit at the bottom. Anyone got any ideas?

Thanks,
94E