I decided to modify my solar powered cabin exhaust fan to be a bit more practical, now that the weather is warming up.
Previously I had the panel laying in the hatch, but it slid around somewhat when driving and required that I move it after parking. As the sun moves across the sky, different parts of the hatch are in shadow, and the panel voltage drops dramatically unless nearly the entire panel is receiving light. It runs the fan on a cloudy day even behind tinted glass, but shadowing even 10-20% of the panel with my hand on a bright day shuts off the fan.
So, velcro:
