This is my first attempt at designing anything in tinkercad and anything 3d with actual measurements(I dabbled in blender years ago). It's pure functional and almost no aesthetics.

This is based off of https://www.thingiverse.com/thing:3748289

I wanted to mount my echo auto to the window with suction cups up by my rear-view mirror mainly to eliminate any wires running down across my dashboard console.

I had to modify the inserts for the magnets because the 2 magnets from the sides weren't strong enough to hold the echo. All I did was open up a large square instead to fit 4 of the same 12mm x 2mm magnets. I inserted the magnets during the print, though you might be able to get all 4 in from the sides after the print. The magnets do move around a bit if the echo is not mounted. A little glue into the openings would probably solve it if it bothers you.

The suction cups to fit this can be found here: https://smile.amazon.com/dp/B073S5TX8W
The magnets here: https://smile.amazon.com/dp/B076NVJ82G

Update 9/17/19: I took some more time and cleaned it up a bit. I made inserts for 4x magnets so you don't need to insert them during print time Again, you might want to glue the magnets in, though when they're all inserted, they seem to keep eachother in ok. I also rounded the edges a bit better(I'm still learning). Both the .obj and .stl v1.2 files have been added.

I think this might need to be printed in PETG since I think I notice the one currently mounted to my car windshield is sagging a bit from sun exposure.

Update 4/27/22: I'll be redesigning this sometime soon to have stronger magnets and be a bit better looking