Your decals do not require much maintenance, but you do want to make sure to keep them clean. Simply hand wash the area of your vehicle that the decals are installed on, never use a pressure washer on the vinyl stickers. Upon washing them, if you notice any peeling or cracking, you may want to consider replacing them soon to keep your vehicle looking great and to keep up with US DOT compliance.
Magnetic signs do require a little more maintenance, especially in winter, and in areas where road salt is used. Please remember to remove and clean your magnets often as this will prevent dirt and moisture from building up between your vehicle and the back of the magnet. Dirt and dust will weaken the magnetic bond. Always bring your magnets back to room temperature before installing them back on the vehicle after a cleaning. Install them flat so that air can't get underneath them. Lastly, to prevent damaging the magnets, always store them indoors and never inside your vehicle.
Using this cleaning guide will help keep your signs looking amazing and lasting!