>I have a Philips DC-777 AM/FM/SW/Cassette radio.  They are no longer
>available.  When it was installed, it was necessary to run two more
>wires back to the rear speakers because the VW radio was grounded
>differently.  The installer skillfully used the same ceiling route as
>the other two wires that were already connected, other installers
>might not care and will string wires back there under the floor.

Philips still produces SW Radios but not the DC-777. I just got a
special offer for a FM/AM/LW/SW with CD-Player for DM 400.- but
can not remember which model. Independent of what VW does, you should
run two wires between the radio and a speaker independent of it's
grounding. Most radios have differential driven speakers.

Helmut
'80 Camper