Good thing someone brought this up. With the summer season, cars tend to heat up inside and outside so don't leave your gas magazines there. Here's a video clip of a WE M4 Gen 1 Gas Magazine that exploded and caused damage to the windshield of a car. With the heat build-up, gas expands so if you're putting your gas magazines inside the vehicle, and the walls of the magazine may be thin enough to fail in preventing a gas explosion. Please ensure that you empty them first. Good thing the explosion didn't cause any injuries to airsoft players nearby.