Some friends of mine and I do road trips a lot... we sometimes end up driving through the night 'cause a couple of us can drive for hours and hours without much effect (as long as we can sleep at the other end!). So a friend of mine made a CD he calls 'Break Glass In Case Of Emergency', for when we're all exhausted and we have to last that extra 15 minutes till the rest stop. I highly recommend doing that, lots of loud, rollicking songs you want to sing to or dance to, to keep you awake for that last 15-minute push!