I've been researching solar also for my 19'CCD. The manual says that it is an option and the dealer said that they are pre-wired. I called the Factory and was told that they are indeed wired for it with the plugs either at the top of the upper fridge vent or lying just above the fidge (removel necessary). The control wiring harness is 'supposed to be'
in the front closet wall just below the tank monitor panel, and the upper wiring should be tucked away inside the air conditioner channel (remove ceiling control panel of A/C).
I haven't started tearing into mine yet, but plan to do so in the near future. I have also been in touch with Intermountain Solar (A/S uses them for OEM), at 1-800-671-0169. Very helpful and knowledgeable about capacities of the panels, how many watts you need based on your requirements, etc.
Give them a call if you are looking to duplicate or improve on the factory set-up. I think I will be going with their equipment.