I've been using a round magnet mount (looks like what bcbbanga4l posted, but with a different brand) for a while with my Moto Z Force. I love using the magnet mount. I picked up a Pixel 2 XL a few days ago (good discount), and picked up a magnet mount from Walmart for $6 with metal plates. I put the included metal plate inside the fabric case I picked up on clearance, and it works great. I can't find it on their website, but it was sitting on a bottom shelf in a tiny cube box. It has a ball joint to aim the plate a bit, and the clamp for the vent is sprung, not just a friction wedge. For $6 I was impressed.