My '12 does this as well. I have to hold the nozzle the whole time while filling, and usually can just barely squeeze the handle. I generally put paper towels right at the base of the fill hole to try and catch the burps. I also have to listen very carefully for the sounds of air rushing out of the fill hose vs the vent. I thought at one point the vent line was kinked, but I couldn't find anything when I pulled it off of the tank.