I don't know about the Panasonic factory inputs (these are most often proprietary) but you can easily use a cassette adapter with decent results. This is what I do when I use my wife's car and want to bring the empeg along. All you really need is an RCA patch cable (probably a 1' or 3' will do, get a good one, preferably shielded). One end of this is going to go to the empeg line outs on the back of your sled. The other end is going to be somewhere under you dash. At this end you'll fit an RCA to 1/8" phono (stereo) converter. Connect this to said RCA cable. On the 1/8" male phono plug you're going to put a female-female stereo converter. With this setup you can plug in most any cassette adapter and off you go. If you're clever about the cable routing it won't even look too bad. You might have to switch the RCA adapter's left and right channels to get the correct balance.

Mind you that a lot of people on this bbs (myself included) are of the mind that having the factory system as slave & using aftermarket amps, speakers is really the way to go if you have the coin after sinking 1 large + into your empeg. Components make nice Christmas, Chanukah & Kwanzaa presents! The sound quality can often vastly improve on factory.

Anyway, the RCA cord & two adapters will run you $20 max. I don't know what the casette adapters go for.

just say you weren't paying much attention...