i assume they are double sided tape because that is what everyone does when they install them and im sure they come like that from the factory. however, you never know what someone would do to hold them on.
they dont have screw holes in them, but if i were to buy another set id screw them into the car because they are just too easy to rip off and walk away with them. i would use the markings where the mold was filled to mark holes and go from there. most likely the set that youre ripping off the car are just double sided tape though.
