As an old desert rat, I would never go anywhere without a full canteen, and I usually throw in some means of heating, an alcohol or canister stove,so I can convert that water into a nice cup of tea, as well as for other ourposes. My car is so equipped right now, even siting here in balmy soCal.

I am not so sure that five gallons of gas in a container of unknown specification is a very good idea. Better to be sure that the gas tank is full when embarking on a trip.

As long as you are equipping yourself, throw in a tow strap.