I dont have a G3, but on my G4, i had to cut a little bit of the hole that goes into the fender for clearance. I guess it depends on if you are using a hard pipe or not. I have aluminum pipes, so there was no way for me to manipulate the pipes to fit, I had to manipulate the car. haha. Like the others said too, take off the black plastic thing in the wheel well and you will have access to the fender area. Take off your tire too, makes it very easy to work with then. remove every part of your old airbox, it just gets in the way. Good Luck! Post pics too!