I have it on my 04. (the original owner had it installed at delivery) The only issue that I have come across, is that it is spotty. Looks like it is permantly water spotted. But from 5 ft you can't tell. The kit installed on my car, covers the bumper, first 18in or so of the hood, the first 6 in of the fenders, the mirrors, and the front lower arch of the rear wheel opening.
I remember a few months ago a member on here had his removed. The factory rep. removed it. Took almost 2 days. Here is the link:
http://forums.g35club.org/zerothread/366557