I’m using a Scosche Magicmount, although other magnetic mounts and the like are available...
Small plate stuck to the back of a Spigen hybrid case (avoiding NFC and Qi areas, so near the bottom), with the mount sitting on the dash in the A-pillar area next to the door. Mount’s got a rubberised coating and the magnet’s strong enough that it held on to the phone fine around Loch Lomond a few weeks back (horrendous potholes).
Got it fitted at a height that my (current) iPhone 8 and Mrs whiskycycle’s Pixel 2 fit the same area and don’t rattle about.
Spigen themselves do a decent enough version (Kuel, I think it’s called).