iPhone slides off MagSafe charger

Hi, I've got an iPhone 12 mini with an Apple silicon case that has the MagSafe ring inside of it. It will charge ok overnight on my MagSafe charger but if I try to use it with a car mount it slides off the mount without any support. Is there any way to get the phone to connect with the MagSafe charger more securely or do you have to remove the case to use the chargers vertically?