exhaust fumes have been a bit of a problem for me when i drive with my window down. not too long ago, i discovered that if i rolled down the passenger-side window, it evened out the suction affect, and fumes were barely noticeable. then, as a "i've tried and fixed absolutely everything else (except pipe extension), i replaced the 2 big rubber plugs on the hatch....and put a bit of metal tape near the hatch latch to help seal there, and wa-la! no more fumes. it's a wonderful thing. hope this can help someone breathe a little easier.