Fill the blitz about 3/4, so it's not expanding in the summer heat. Pour it into the tank and replace the gas twice a year, gasoline goes stale.
I've known folks to store a Blitz in the passenger compartment of a vehicle. Or inside a van. No worries.
The only guy I knew who blew up a vehicle had a propane torch in the back. Aparently the valve opened, and filled his truck with propane. The guy's a smoker, and mighta coated his nasal passages with tar. He says he threw something in the back which caused a spark. My guess is he leaned in to light a cigarette, wasn't paying attention. Or maybe was too smoked up to smell the odor they put in propane. Truck was a total loss, and he spent some time in the hospital burn ward.
Lantern, heater, Torch.... take the tank off the tip, guys. Much safer.