I agree with the pp, Robin, about renting carseats from the car rental agencies. We did it once and used the seat only long enough to go to wallmart and buy a suitable carseat for my dd. It was dirty, the fabric was worn and a very old model. We bought a lower priced, lightweight carseat that got used during that trip and lots after for nana's, auntie's and other trips.
Like Justthat mentioned, there are several great, lightweight and affordable carseats that would cost less than the $150.00 rental price and give you peace of mind. Just make sure they meet the height and weigh requirements you need or even better convert to a booster for use later when the kids are older.
Or if you don't have the huge britax type seats, consider just bringing them with you, BRU has a great carseat bag that can be worn as a backpack or rolled behind you. This way you save $ and can be sure the seats are in good condition and safe.
Another note, if you do rent the carseats be sure and check the installation or re-install them yourself. Many of those working at the rental agencies don't understand how to install them properly.
As far as some of the other questions popping up:
You can't use a carseat on ME or Disney Transportation
You are not required to use a carseat on the airplane but the FAA and AAP
recommend you do for children up to age 4 and 40" lbs.
If you want to use a carseat and are worried about seat kicking book the seat in front of the child for a family member and take off the childs shoes. (DH usually gets that seat!!) Make sure the carseat has a sticker indicating it is approved for use in aircraft.
Booster seats, (without an integrated harness) are not allowed to be used on the aircraft.
FL law says children through age three need a carseat, 4 and up are legal in a seatbelt.
Hope this helps
TJ
