Comfortable on Vacation?

Brayden screaming in the car for hours.  Brayden screaming for the first couple of days on vacation.  It was not unexpected for him to spend time screaming or crying.  We hoped and prayed it would not happen (Luke prayed the nights before vacation that Brayden would be happy).
What makes him uncomfortable?  What makes him comfortable?
I do not know.  Nor do I know why he liked to position his legs like this.

Or his head like this.

Some how this is his way of getting comfortable on vacation.