Made up air scoops for batt. and ESC cooling, note the air exit at the rear above my ESC.
Extra cheater on the belly for more cooling of ESC and Batt.
Forget about drinking straws, it wouldn't have any cooling effect!!! No idea where your ESC is mounted, but if you are concerned about running it hot place it in the position where part of its heat sink is exposed to the air intake or exhaust outlet. It might take some foam surgery and re-wiring. Small air scoops or cheater hole is another alternative, as encl. pics.