RTI & Reversing cam

Hi Guys and Gals,

I'm putting this on here cos I know others have the same CD Driven RTI Sat Nav unit fitted with the pop up screen.

I have a 2004 C70 2.4T GT Auto conv, With the Standard SC901 stereo with 3 Cd player and 6CD changer in the boot.
Also fitted is the now obsolete CD based RTI unit (Still works perfect but discs WAY out of date)

Is there anyway I can connect a rear view camera to utilize the pop up screen, which I presume is analogue.

My CD Sat nav works ok but is so far out of date, even the latest Cds cannot find places in my home town of Bangor, so is of no practical use whatsoever so might as well try this.

cheers