I tend to do a fair amount of work in my truck now. I have a Ram Mount Laptop holder in there already. So I designed a holder to slide my WiFi Hotspot into. The WiFi Hotspots I am familar with aren't very heavy so not much structure is needed to physically hold the thing. I designed this with lots of void space, but if you print it vertically no supports are needed at all.

You can use one or two 1/4 x 20" bolts to mount this thing to the front of slide of you laptop tray. I designed it to have two oversized holes in the front that line up with the mounting holes so you can get a screwdriver in there to tighten things up.

I put mine on the side out of the way as seen in photos.

With the cutouts on the holder you can see most of the screen, get airflow and use minimal filament. Again as well as not needing supports.

The bottom has ledges the hold the hotspot in the holder but lets you keep it plugged in to maintain charge, if you want. As well as if you spill some in it, it won't pool.

I printed this with PLA, but you may consider something that does better in hot enviroements.

I used 100% infill but you don't have to, the first one I did was 30% and it was quite stiff.

.4mm Layer height.

Zero supports.

Brim to keep things from moving around as it printed.