If you have the limited non-nav stereo, it seems that there are hooks for a backup camera built-in on the stereo.
Check this out.
Put the key in acc position.
Turn off the stereo.
The holding down '6' and turning tune dial until a firmware version info screen comes up(it takes ~5 full turns).
Press the tune dial in once and you get the 'firmware update' screen.
So there is potential to update firmware for things like bluetooth, ipod interface, etc
If you press the tune dial one more time, it actually brings up the CAMERA!!!
Well, there is no camera attached, but if you connect it, presumably, it will show the rear view camera on the stereo screen. Currently when I get to that screen, it shows a blank screen, with backup markers. If I press some other number, it turn on/off the back up marker, or brings up different size markers.
I would assume that there is a video input jack in the back of the HU.
In the regular screen setup menu, there is even a setting for choosing NTSC or PAL video format.
I hope someone would try and hook up a camera to the stereo to see this really works.
Maybe there's even a way to have it automatically switch the display to the camera when you are in reverse.
Myabe down load the firmware from a forester or outback?