I think a scientific test is going to be difficult, the instrumentation would get jammed by dog slobber.

Vernon

: To blow off the hatch off, the wind would have to somehow either: 1) get
: under the hatch enough to lift it up, which would be very hard, since the
: hatches are flush

: -or-

: b) be blowing so hard that the Bernoulli effect would cause enough decrease
: in air pressure above the hatch so as to have the lid be popped off by the
: pressure under it. That would have to be a lot of wind to be able to
: overcome the bungees. Let's assume a 10" round, flat hatch of a kayak
: on a car moving at 70mph , laminar airflow, 4 bungee attachment points
: providing 10# each, one atmosphere ambient pressure, and a dog with his
: head out the passenger's window. What would the headwind have to be to
: overcome the bungees, and would the dog still have any fur left on his
: face?

: hmmm...

: Dean