mmm, it didn't work with the Bose in my E Class though. It has no preamp inputs but speaker level inputs. So the only thing I could do was replacing it with an aftermarket amp.
Instead I replaced the oem headunit with a 'Comand' (oem tuner, CD, tel, TV and navigation unit). These have an AUX IN so I can hook up the empeg.
Of course, since the Comand is a double din, it leaves me no room to fit the empeg .... well duuuuuh. I'm trying to fit it in the ashtray, but I haven't been succesful (yet).

Frank