Regarding your slide-out solar panel idea.. I have seen that a few different ways, and there is a youtube video with pneumatic actuators too..
I am changing the panels on the top of my E350 ambulance to several 250 watt residential panels I got a deal too good to pass on.
My idea, which may fail spectacularly, is to mount three panels across, with the two outer panels having piano hinges along the outer edges mated to two more panels, (photosensitive part to photosensitive part) which I would flip "open" when parked.
When closed, I would have one (center) panel exposed (250 watts), when the outer panels are 'open', I would have five panels operating with "1250 potential watts"
My brain says it will look like some sort Roger Moore era James Bond "doomsday satellite death laser" device.