Ugh, so how do you store water in cars? I usually get a block of bottled water and leave it in the back seat. This serves as my water supply when my canteen runs out of water, when I neglect/forget to bring my canteen, or just when I get thirsty. This is convenient, because the bottles are moderately sized, and I can replenish easily at the local supermarket (one plastic-wrapped block for $3). Now I'm discovering that while I might not get breast cancer, I might get started with puberty early.