The magnets will fuck up important sensors in your phone. I love the look of the back of my s10, it's the white one that has some extra flair to it. Forgot what it's called exactly but anyways, I bought this phone and use clear very thin cases. I also work for Grubhub and attach magnets to the back of the phone, on the case. (On my s9 I now know why my charging port started fucking up,)

So here is my experience with the magnets on my s10: It kept messing up the compass and made it impossible to use gps because the sensor that shows what direction you're facing and heading in when driving would get messed up by the magnets and I'd try to recalibrate the sensor, it would be good for an hour or so then just get completed undone. I took the magnets off the back of my case and stopped using the magnetic car mount and the sensor has been good ever since.

I'm so thankful I learned this about the magnets just a week or so after buying the phone because if I had kept on doing what I did with the magnets all day driving for work and them just constantly on the back of my phone, I would've potentially screwed up multiple sensors and important things in my brand new s10 permenantly and not even know how.

So that's my experience. Take from it what you will, but if you insist on using magnets and a magnetic car mount, I highly recommend using a very thick case and keeping them as far away from the bottom of the phone or camera as possible. Which would be pretty much impossible.