Car magnets usually stay in place while the vehicle is in motion as long as they are applied properly. Magnets stay on best when placed on areas of the car that are flat or slightly curved. Car owners should only apply them to metallic areas with minimal non-metal fillers.
Moisture or air pockets underneath a car magnet can cause it to fall off, so it is necessary to dry the surface and smooth out any air bubbles during application. Vehicle owners also should not place the magnet on top of any protrusions, such as decals or moulded areas. Removing magnets while washing the vehicle helps retain their sticking power. The car should be completely dry before putting the magnet back in place.