We are flying, staying onsite, not renting a car and using Magical Express. Our kids are 7, 4 and 1 and we use booster and car seats here at home. On the plane, the baby does not have his own seat and I think the 7 and 4 year olds can get by without car seats on the plane. This is the first time not renting a car, so we are thinking of leaving the car seats at home. Can we?