It is extremely dangerous to leave a gasoline can in the trunk of your car. If the trunk heats up from the sun, vapors inside the gas can expand and the increasing pressure will allow the vapors to escape. As the vapors accumulate, an explosion could result.
Also know, can you store gasoline in plastic containers?
If you use another plastic container, the gasoline will gradually disintegrate the plastic, and it can seep out. This is actually pretty dangerous, so stick to plastic containers made for storing gas. There are also metal containers for gasoline, and they are generally considered to be better than plastic ones.
How long can you store gasoline in a plastic container?
About 3- 5 months in a sealed container. 6-8 months with fuel stabilizer added. Recommended maximum storage 1 year. The API (American Petroleum Institute http://www.api.org/) recommends that gas is not stored for more than two years in an approved container without fuel stabilizer.
How should gas be stored?
Keep gasoline containers tightly closed and handle them gently to avoid spills. Gasoline is a flammable liquid and should be stored at room temperature, away from potential heat sources such as the sun, a hot water heater, space heater or a furnace, and a least 50 feet away from ignition sources, such as pilot lights.