Bongo Fury

No Manifold noise or blowing from the exhaust I am sure, interested in the other idea, does anyone know if the Bongo has the same? Hopefully I don't need to take the bumper off to see, still poses the question though how do the fumes get from the rear to the heater vents.

I think you do have to take the rear bumper off. I seem to recall coming across something like this when I had mine off recently for respraying