My family and I are going to North Carolina from Toronto next week. We will be taking our Complete Air but not our Maestro, since DS is only 11 months old and can fly for free as a lap baby (I'm comfortable with this), and i refuse to put a seat through the checked baggage. I will put DD (4 y/o) in the CA on the flight and then adjust it again for the car so that baby DS can RF in it. Will need to rent a seat for DD though. We will be renting a car from Hertz or Budget most likely. How are their seat selections?