I know that all too well
Took a coworker over to another building and went around the corner not that fast but I had some calibrated weights in the back with one seat folded down. The other side i had my fire extinguisher in the seat with some floor mats over it drying due to a leaky sunroof. Well after going around that corner the weights fell over on top of the mats with the extinguisher and it set it off. My friend screamed, I thought it was a fire and we pulled over and jumped out! I started to laugh out loud as it must have looked like a bad 80's movie with white powered going ever where! Lucky for me the nozzle was pointed in the seat crack and contained most of it and the mats also helped.