>
> Now my question is has anyone (or can we) come up with a nifty way to
> remove
> this built up heat more rapidly than occurs naturally by loss through the
> walls of the vehicle by, for example, installing a small fan in such a
> way as
> to exhaust the hot air while pulling in cooler outside air.

I cannot find it with a cursory google search, but there is a company
that manufactures a solar-powered ventilation fan that goes in the
window opening.  It mounts between the window glass and the top of the
door opening and is held in place by the glass.  Maybe someone else has
seen these.

Mike Snow