Having a "little" experience with the power of the wind on sailboats....I've learned to have a healthy respect for the power of the wind when one is moving down the road.
I drive at 70 mph to most of my fishing spots. The wind can pull ANYTHING out of a boat at those kinds of speeds. I've seen things blow out of my boat MANY TIMES. Don't leave anything in your boat that you are not willing to lose.
To illustrate that point......I was driving down a highway in Houston a year or two ago.
In front of me was a big 18 wheeler with a load of steel plate on it. 4 x 8
sheets of solid steel plates were stacked on the truck. They were not tied down, apparently. With the help of wind power, one sheet was lifted off of a stack and flew 100 feet down the highway.
I don't know the weight of a sheet of steel that big, but it was heavier than anything I would normally leave in my boat.
It came close enough to me to guillotine my head off had it come into my windshield. Instead, it hit the highway and sparked as it slid 50 feet across the lanes.
Wheeew...I learned an even better appreciation for the power of the wind that day. I called 911 hoping someone would stop the truck. The driver, apparently, hadn't tied down its dangerous load.
R