Here's a tip for those that don't want to buy new bottles.
When I recap my plastic bottles for travelling, I ever so slightly squeeze the bottle while replacing the cap tightly. If you're going from a lower temp environment to a warmer one (i.e. house to car), the liquid will expand a lil' bit. By capping while squeezing, you are creating a slight vacuum. As the juice warms, it will have room to expand without leaking.
I've been fortunate thus far, no leaks. YMMV...