Do I need a wireless-charging car mount, or is a plain magnetic one fine?

For most drivers, a plain magnetic mount plus a USB-C cable is cheaper and more reliable. Across r/MagSafe discussions in our source pool, wireless car chargers commonly run hot and several owners reported throttled charging or, in one case, a damaged Qi coil. If you do want wireless, look for active cooling and a true Qi2/15W spec rather than marketing claims.