Ouch!
I'm glad you WEREN'T in the truck doing 75 down the freeway, too. Wow, talk about a cautionary tale!
Now, just to put this all into perspective, folks need to know that the inside of a car or truck parked in the sun can easily reach 160 degrees F, a temperature that is dangerous to ANYTHING IN AN AEROSOL CAN. Deodorant, hairspray, bear spray (as the OP found), spray paint, you name it. And any of those things bursting on the dashboard at 75 on the freeway is going to cause a wreck. Of course, had you been driving, you'd have not tolerated 160 in the driver's seat.
But the lesson here is that it is a really bad idea to leave any such product INSIDE your vehicle when it's parked in the sun.
