One trick that may work (in theory) if you leave the tape deck but connect the riocar rca cables thru a converter (for bose stereos) to the speaker wires running from the tape deck to the headunit. This may not work if a tape needs to be in the player for the headunit to switch into aux. mode. I don't know if this will work and before you try anything like that I would make sure you know what your'e doing and BE SURE you know what wires are what.