The Google WiFi does not come with an option to wall-mount the units. No mount, no screwholes or anything.
I wanted to wall mount the base unit at the same spot where my old router was mounted, so I made a thing!

This hanger is very simple. It is a small shelf for the Google WiFi unit to sit on. The shelf is mounted to the wall by hanging it on the power adapter. The power adapter is plugged into the wall through the wall-mount. The wallmount will not come off the poweradaptor since the power-cord is blocking it. But since the hole for the poweradaptor is a little oversized, the mount will tilt forward a little. I solved this by securing the mount with a zip-tie around the power adaptor.

This mount will only work with a horizontaly mounted power outlet. Hopefully I will get some time to make one for a verticaly mounted power outlet as well.
There is some room behind the Google WiFi unit for managing the powercable and network cables, but i recommend not using this for much more than the powercable.