I don't have my Tesla yet, but the solution I just started using in my Acura is the Mophie Charge Force magnetic wireless charger. Unfortunately, the only car oriented version they sell includes a vent mount which works fine in my Acura, but I haven't tried it in an X yet. The advantage is that you get ease of a magnetic mount with charging. The disadvantages are price, vent mount, cord leading away from the mount, and only compatible with their charge force cases, but they have them for recent models of Galaxy and iPhones. Also, many people may not need the overkill of a battery case combined with car charging.