So what spare fluids do you carry in your vehicle?

My plan was to use a spare ammo can to contain them, plus seal each bottle with a food saver, to prevent messy leaks.

I have space for 4 or so bottles, and was going to do 2 quarts of 5W30 oil and 2 quarts ATF, but I am not sure that such a little amount would really help me.

So how do you store your spare fluids, and what do you take along and what do you ditch?