Google Pixel 3a Case magnetic

I remixed the Google Pixel 3a Case, to embed a washer in the case, to mount my phone on a magnetic phone holder in my car.

OpenScad file is included. Compared with the original from jpickens, increased width of the back to add the washer, and changed the fingerprint hole.

I used a Washer with
inner diameter = 8.4 mm
outer diameter = 30 mm
width = 1.5 mm