no glue, they dont come with any adheasive or any kind already on the kit, its bare fiberglass, the way to install is first fit it make sure it sits where you want it and goes even with the body, then you have 2 choices, I've done both and perfer the 2nd choice, first regardless you screw in the ends, thers a lip on both sides of the peace (all 4 peaces of kit) that wraps into the fenders, 2 screws go in to the fender lip to hold it in place, then you get the choices, you can get 3m automotive accesory tape and line the edges of the kit and stick it to the body, which I had for a while and was not thrilled as it did not hold my kit well, maybe yours will be better and hold but who knows, I now have it bulted to the car its a much stronger solution, I epoxyed bults to the kit and drilled holes though the body, (if you drill holes though the body be very sure to put a coating of paint or clear coat around the hole so rust does not start) also be sure the whole is sealed well, rubber washers does it just fine) as for the rear mine was plenty tight that it just snapped on and only needed the screws in the wheel well.
if you do get a used one be sure to clean off any old tape/glue or whatever before applying any new tape.
what kind of tape exactly do you use? Do you know the name of it or the name of the brand? thanks