Most of the wireless charging cases for Apple use the Qi standard, so almost every case and charging pad you will see uses Qi. GM uses PMA, which is what all of the Android devices use, as such the standard Apple wireless accessories will not work with your GM charging pad. You need to get one that is PMA, I know the Bezalel has one that does both Qi, so you can continue to use the Apple charging pads you have, and PMA so it will also work in your GM car, I have one for my 6S and works with both flawlessly, unfortunately, I also have the 6S Plus and while they make the charging cover, it seems too big for my GM charging pad and does not work.