a friend of mine had a vw rabbit that had magnets on the inside of the bumper and on the licence plate bracket so he can drive all day but when he went to a show take it off and have no screw holes tape goo just a clean perfect painted bumper also the magnets were wraped in felt as to not scratch the bumper

 

i use the 3m Velcro, take it off when im driving and put it on when i park it, but in chicago you wont get a ticket while driving cause the cops are to lazy here to pull u over, but if your parked the dont have to get outta the car and will write u a ticket.