She's not old enough to really be considerate - you can have rules, but this is too young to teach real "respect" - they just haven't reached the development stage when they can internalize this. For example, you can teach a child this age about the "no hitting" rule but you can't really expect her/him to feel true empathy. A lot of preschool teachers actually have mixed feelings about making kids say they are sorry - first of all, they AREN'T sorry because they can't feel it yet. Secondly, they think "sorry" makes it all better, and of course it doesn't.
I think you were under very difficult circumstances and actually that she did really well. An incredibly long drive in a car seat, a lot of new people and new surroundings, and a disruption in her routine - wow! At home you have an environment that is conducive to sleep, as you said. On the trip, you didn't! So she talked to herself (to entertain or calm herself) and told you she loves you (to comfort and reassure herself) - sounds like she did great! In the future you can either skip the trip or get a suite with separate rooms/sections for the kids and the adults. It's more money but if you didn't enjoy this trip, you'll know for the future.
PS Hope you enjoy your Prius as much as I enjoy mine!