Spend a couple extra bucks and get the one that pivots. Makes all the difference. Also, don't skimp and buy the cheap version of this (like from Wish.com), the magnets are too weak to hold the phone. I've tried several. The type below is the best design.
These magnetic phone holders that you stick in your car's AC vent. I stick my phone on there (if your phone isn't made of metal, they include metal plates to either attach to your phone or slip inside your case).
People always ask me how my phone "just sticks like that" because it's so easy to use. The magnet is surprisingly strong, but not OBNOXIOUS. I can pull my phone off easily, and it doesn't fall off when I slam on the brakes hard enough for my purse to fly off the passenger seat.
I have tried SO MANY PHONE HOLDERS and this is the best thing I've found. I hate the ones that attach to your windshield because I feel like they block my friend of vision and I don't like the ones that your phone clips into, because it's always a pain to get your phone out of it. I bought that one that had the green sticky stuff and it was the absolute worst. This one fits right above my radio buttons, so it's in my sightings but unobtrusive, and within reach if I need to change my map or something.
I've bought these for my brother, my boyfriend (he used to drive with his phone in his lap and it drove me insane), one for me to put in my boyfriend's car, my other friend and her boyfriend, and everyone loves them.