Ventilation for Aft Cabins

[capta]

We have a similar problem w/ our P-530's aft cabin. The forward half of the bed has great ventilation, but aft by the headboard there is no air movement. Even with fans, there is just no way to get the hot air out aft, it just circulates.
When I was young, there were funnels that had a small forward cone and a much larger cone aft, which would draw out the air through a deck plate (usually over the galley). I cannot find these anywhere; have any of you seen anything like this for sale anywhere?