I've solved my fume problem. First off, get your motor running right so there isn't an excess of fumes. Then pull out all of the plastic stuff in the back. Go to the store and buy two tubes of silicone caulk and put it all back there covering any seam to the outside. Spread it around the tail lights and where your gas tank vent lines go through the body. Then replace your hatch rubber and you will be good to go.
-jeremy-