DS will be 4 in August and is around 44 inches and 40 pounds. He uses a booster at home (a lot of his friends don't) and we're debating whether we should take ours from home or not. We're flying and only renting a car for 4 days out of 10. National charges $6 per day to rent one which would cost almost as much as buying one. DH thinks he'll be fine without one, but I'm more cautious and would like to take one. Any opinions? If we check it in with our baggage, do we have to cover it with plastic or something? 9 more days!!!