I got a full size Jimmy (85). When I have the rear window cracked slightly, or all the way down, anywhere in between, I get exhaust fumes in the cab. Anyone know of any way to route the exhaust or any mods to the window area? I have seen those little wings that are pointing down, mounted just about the top of the glass. Anyone? Any suggestions? Also, if this is the case, I can see it being the same with the top off.