L.R.
I have the Cares and never used it. Waste of money.
I just got back from a trip with my daughters, 4 and 2. I thought my 2 year old would never sit still in the seat, but at the last minute I decided to not take her car seat (I went alone) and it worked out just fine.
I looked into all these options before going. I read that the car seat adapter is really just a luggage cart, which you can buy cheaper. There's also a product that allows you to wear the car seat like a backpack if that's something you're interested in.
Everyone else has written good ideas about what to bring as far as toys. Snacks are the best. One thing I found...it's really annoying when all the little toys fall on the floor. One thing I wish I had doen was bring triangular crayons instead of the regular ones....lol