That's right, a compact rigid 100W Solar panel that fits down inside
Westy front luggage rack.

Special discount today for Amazon folks, $90 shipped free.

https://www.amazon.com/Renogy-Monocrystalline-Solar-Compact-Design/dp/B07GF5JY35/ref=sr_1_1?keywords=solar+compact+100+watt&qid=1563317736&s=automotive&smid=ATVPDKIKX0DER&sr=1-1

AFAIK this is the largest capacity rigid panel that fits down in that
spot. Mount it or leave it free in there so you can lift it out and
place it where sun is when you are parked in shade.

Here is a photo of it inside a Westy luggage rack.

[img]https://www.thesamba.com/vw/gallery/pix/1925929.jpg[/img]

Be sure to get the one with these dimensions:
42.2 X 19.6 X 1.38 Inches

Mark