> And when these vehicles were new, they *were* pretty darn
> air-tight.  Ever try to close any of the doors with seals, felts, etc.,
> having been newly installed?
>
> you still had to "crack" a window when you closed the door from the
> inside or your ears would pop.
>

In fact Volkswagen made reference to this in their owners manuals.  The
Volkswagen Bus owners manual (straight through '79) actually noted that the
doors might be easier to close if you left a window cracked open, because
otherwise the bus would be airtight and the air would have nowhere to go.

-Ron Salmon
 The Bus Depot
 http://www.busdepot.com