Answer
Every state has its own rules and regulations for vehicle signage, so unfortunately there's no standard rule. Many states regulate car sign material, others limit the size of the signs, and some even prohibit car signage completely.
To prevent a citation or any other legal complications, we suggest checking with your state's Department of Transportation before placing an order to determine what car signs you can legally display. As a nationwide company, Signazon.com cannot guarantee the legality of any car sign products for your specific state.