Notes for a road trip with preschooler and toddler

My 4-year-old told me the other day that he would love to spend two days driving to Texas. Even when I told him he wouldn't be able to ride his bike or run around, he insisted he'd love it.
Nonetheless, the longest road trip I'm planning on before they're ... well, ever ... is the 3-hour trip to the cabin. In preparation for summer, I created a Google doc with a list of supplies, over half of which is dedicated to the drive.

Then I arranged to send the kids on the first trip of the season (the one during holiday weekend rush hour) without me. I am sure, however, that my precision packing will make for a lovely ride for Daddy and Papa. Here is an excerpt from my emailed instructions:

Important nighttime things are in open zippered pouch of grey suitcase. Except for toothbrushes, which are in front closed zippered pouch. There are DVDs and headphones in side armrest, if either of you has a laptop w/ DVD player. There is an iPod, charged, in front cupholder. Songs under "Music for Books" can be played along with the four books in the seat next to Z. Other books also next to carseat. Also, auto Bingo sheets in one of the books next to Z.
Each kid has a backpack of things to do in their seats. There are two filled water bottles next to W. There is a bucket of animal crackers next to the driver.
I'm sure W will explain the seating arrangements, but the current configuration has Papa next to W and behind Z, and Eric driving.

There is sunscreen in one of the front pouches. There are helmets loose in the trunk, and I'll put W's bike in there too. And Z's pack-n-play + monitor.

Any questions, call me :)
Have fun!