Lighter weight option. Needs 2 screw-type suction cups and approx. 30 grams of filament.
Model measures 150 x 50 x 20mm. Suction cup hole measures 6.5mm diameter for a 5mm screw.
Printed mine in PLA, 0.3mm layer
FreeCAD files included to adjust as you wish
version 2
Found warping with the single suction cup model after one week in sun (PLA). Improved durability with +1mm thickness and second suction cup pocket
The author marked this model as their own original creation.