I did notice a smell at one point after moderate acceleration. It was not combustion fumes as i know them. Could it be a product of the extreme temperatures produced by the twin turbos?
I also noticed a lot of cool air draughts on my hands when I was working on my electrics behind the drivers seat. The air seemed to come from the punched holes in the lower B pillar frame.
I am thinking lots of air is finding its way in through van cavities,and bringing in whatever with it.
My thought to mitigate this would be to create a natural convection exit, as high as possible, so air passes outup high.
Or open a window.