After watching countless YouTube videos, and reviewing postings on how people configured their Vanagon's and other camper vans with Solar Panel(s), I determined I didn't want to goober up my van with wires all over the place in plain sight.  I also wanted to have options as to where to position while camping (van in shade, sun near by... optimal).
https://photos.app.goo.gl/j5PS7uHndHNmayZ29

So, I researched flexible panels, higher wattage, great warranty, and something that would store under the rear cushion.  I selected a SunPower 110W. (also available in 170w) https://tinyurl.com/ybcunwc8  $215 for the panel.

    Panel Dimensions: 45.9"(L) x 21.9"(W) x 0.1"(H) (0.8" including J-Box) 
    Weight: 4.4lbs - Lightweight, Portable, and Easy to Stow
    Power: Rated Voltage (Vmpp) 18.8V | Rated current (Impp) 5.9A
    Flexible: up to 30 degrees - Suitable for Irregular Surfaces
    5-Year power & 2-Year product warranty (no salt water exclusion) - Backed by SunPower

This panel fits easily under the rear cushion, without any noticeable increase in thickness.  I believe the 170w option would also fit!

Next, I purchased plugs and connectors and 12g wire, as well as a Controller (to lead acid aux battery).

I ran the 12g wire from the rear cabinet mounted plug, underneath and through the cabinets, to behind the driver's seat, where I mounted the controller connecting it to my Aux battery via the two inverters (I have a 700w and 500w, the 500w usually is enough and has far less draw when on, and powers my TV/DVD without any problem).

Rear cabinet plug(s): $15 https://tinyurl.com/y7tr4tq6
Wire 12 AGW 25ft: $17 https://tinyurl.com/y8lz8bp5
Solar Wire Connectors 10 pairs: $11 https://tinyurl.com/y836cxel  
Solar Lead-Acid Batter Controller: $16 https://tinyurl.com/ybmvh8of
Inverter 500w: $40 https://tinyurl.com/y7zsoanz

Total invested $314!

I'm very happy with this set-up, as no-one would have a clue that my van has a Solar option... to help with the occasional times we are not able to hook-up to shore power, or if we do some Boon-docking for a night or two.

I hope this inspires some followers!

Jack R.