firephil i live in my car also. in my car cooler i keep lots of water and preportioned jars of Grow!. i also mix in stuff like flax seed or wheat germ and i throw my vitamins and fish caps right in there too. i use large mason jars and tomato sauce jars -whatever holds a qt or more has a wide mouth and easy to load/clean/re-use. definitely glass. plastic blows for protein shakes cause you never really get it clean.
anyway i usually take three jars w/ me a day and just add water, which i have a ton of anyway, and shake it up. i'm usually driving when i mix it .it's not hard and if you live in your car you've already got the skills.
other than shakes i eat alot of apples, raw almonds, and hard boiled eggs.