yes however i wouldnt do it, its not practical to run 12v from there constantly and will break after a while.
also dont go through head liner, much easier to just pop the trim off on the floor and route it down under the carpet ect under the door.
not sure how to remove glove box on mk5 cause i dont have one and this is the mk4 section, i sugest now you know were the grommet is you go start a thread in mk5 section asking how to remove glov box to get to the grommet