When applying an automotive vinyl sticker, start by thoroughly cleaning the area where you want the sticker with rubbing alcohol or soap and water. Do not use window cleaner because it can leave a residue that interferes with application.
After cleaning, rub the sticker with something rigid to get rid of air bubbles and make sure the sticker clings to the transfer tape properly. Peel off the backing paper, carefully place it on the vehicle, and rub it with a squeegee or credit card to make sure there is a firm bond. After waiting 24 hours, pull away the transfer tape, being careful to not remove the sticker itself.