A new product coming from Orion Design to add sliding solar panels to your van. Saw it on the Sprinter-Source Forum. Looks like a good way to get more solar on a crowded van or expedition camper roof.
Products - Orion Designs
Systems (SR2R/SR2S) to double you PV Array size. Systems (SR1R/SR1S) to place under existing roof racks. Side or Front/Rear extensions. Optimized for Class B RV's & awning friendly. PV Array sizes up to 67in [1701.8mm] wide x 64in [1625.6mm] long. Smooth, full extension & maintenance-free...