My 91 300e had two smaller silver amps where your larger black one is the thing behind it is the tuner and preamplifier. The deck up front mine was cassette. Is just a controller. Think of the dash part and the trunk part as being your deck in two pieces. You still should be able to install a new deck. Run new wires to the dash speakers the wires for the rears can then be grabbed at the center console fader and the door speakers will be at the amp in the trunk. Save yourself a headache and install a small amp in the trunk where the factory controller is to run the doors. Run them as mid bass speakers.. You have to run an antenna cable from the antenna to the dash so run the power and preamplifier cables for the amp at the same time go out to the battery behind the glove box