I'm curious about this, too.  I have a Heidelberg IV that I plan to
install in my '82 Westy, but I haven't tried it yet to see how well it'll
fit.  I don't smoke, so if the ash tray interferes with the radio I may
just take it out.

I do need the harness for the Heidelberg IV if anyone has one.  The power
plugs I can fake with push-on connectors, but the speaker plugs are
"special".  If no one has a spare set I'll solder my own harness to the
connections inside the radio, but I figured I'd see if I could do it the
"right way" first.

David Brodbeck, N8SRE
'82 Diesel Westfalia
'94 Honda Civic Si