There are no BMW radios that will fit directly into the e34's din hole. You're only option would be to upgrade to an aftermarket radio. I would recommend the old alpine with the orange illumination. This will match the lights at night time.
I have a e34 with the Eclipse CD7000 but this deck is very expensive. My illumination looks like it was made by bmw and it is, by far, the best looking aftermarket radio for BMW's. There arnt many choices for orange illumination radios, do some research
Greg Mannino
Car Audio.Video.Security.Navigation Guru
Electrical/Mechanical Specialist