Magnetic vehicle signs are better if you want removable, reusable branding that can be taken off when needed. They are a good choice for leased vehicles, part-time business vehicles, temporary promotions and drivers who do not want permanent graphics applied to the vehicle.
Vinyl stickers are usually better for longer-term branding, as they are applied directly to the vehicle surface and are less likely to move once fitted. However, they are not as easy to remove and may leave adhesive residue behind. The best option depends on whether you need temporary or long-term vehicle signage.