MOST optical bus...

[urban_legend]

Anyone come across a (double din) plug compatible head unit replacement for the CDR-23? Hard to believe nothing exist for a simple head unit upgrade to the 21st century.
Aux in, bluetooth, GPS, HD radio, Pandora, etc.,

Even a used Cayenne head unit is looking good now...

[Nimbus117]

Unfortunately not, the MOST system seems to be designed to stop you upgrading. I had to remove the CDR23 along with the CD changer and amplifier. This is a Pioneer 930BT updated to a 940BT, the head unit runs the front and rear speakers and I have an Alpine two channel amp running the subs in the doors:

[jakobv84]

My amp went out and I considered upgrading, but the total pricetag I felt was too steep to get a good setup (new headunit, amp, and wiring) so ended up buying an amp from a scrap yard. I'd settle for just an aux plug-in to enable iphone playback.