We are looking for a carseat for our 17 month old to use while traveling on an airplane and rental car, and the occasional ride in someone else's vehicle. Something easy to install is preferred and not huge/bulky like the Diono she sits in normally. When my older kids were little we had Cosco Scenaras for them, I'm looking for something like that. Need it for tomorrow so ideally it would be one easy to find locally and not online. We have a Babies R Us, Buy Buy Baby, Target, Walmart, etc. nearby. Thank you so much!