I just got the Mountek nGrove Snap 2 and have to say, I really love it. It mounts into the CD slot and holds in place very well but since it's held with a magnet, it's easy to just grab it when I'm leaving the car and put it back on when I'm back in. There's been zero interference with the magnet that I've been able to determine.
Try this goes, goes into CD slot hooks magnetically. Comes with a thick metal stick you slap on the back of your phone. Should honestly work no problem