Hello listees,

  When entering the wake of a Semi Truck while a cross wind is present, I hear
the following:

whap       whap    whap  WHAP SLAM!

It sounds like I've got a blow out or launched a rock into the rear wheel well.
Only thing I can figure is that it must be the rear air vents getting back
pressured.  Does anybody else experience this?  Is there supposed to be some
dampening mechanism in there?  Startles me and my passengers.  This is becoming
a common problem since the primary purpose for my van is to get me and my
windsurgfing gear to the windiest place I can find.

Thanks for any input,
Vernon

'90  Vanagon (no GL)