Wireless charging is one of the few benefits of having a glass-backed phone: it doesn't work through metal, but it does through glass. That limitation in materials may be concerning for folks that want to use steel plates for magnetic mounts, but in our own testing, you can actually squeak by with both so long as you put the plate in the right spot.
Just like last year with the P3XL, I was able to place the metal plate for my @SpigenWorld magnetic mount at the bottom of the Pixel 4 XL's case and it's working just fine.
Can't even see the bulk. Didn't use the sticky either - the pressure between the case and phone is enough. pic.twitter.com/5ZIK7DwJ0b
— Artem Russakovskii (@ArtemR) October 25, 2019
AP's own Artem Russakovskii was able to get the magnetic mounting plate (a Spigen Kuel) set in a position on both the Pixel 4 XL and smaller Pixel 4 where the phone retained its ability to charge wirelessly. Best of all, it worked without any increase in temperature, as you might potentially expect (though YMMV).
Working plate positions for the Pixel 4 XL (left) and Pixel 4 (right).
The only catch is that the plate needs to be set fairly low on the rear of the phone, covering around the bottom third of the back. As a result, your Pixel 4 or 4 XL will ride a bit higher in the mount, and landscape use could be difficult.
Still, if you are among those hoping to use a magnetic plate for a car dock or stand, you can rest easy knowing you don't necessarily have to give up wireless charging for it.