i have 2 girls 21 months apart, and being that my family is from new jersey, they learned very early how to survive long car rides! by trial and error, i learned to pack each child their OWN 'busy bag'... let them each pick out one 'friend', 3 books, a coloring book (i used to throw like 4 crayons each in ziplocks for them... any more crayons then that and i'd find them a month later melted to the floor)... stickers (for the coloring books, NOT THE WINDOWS! lol...), small snacks they can get into themselves, like cheerios, something that they can eat at their own discression but not ruin lunch, a small bottle of water each (or sippy cup), and i'd always throw in a 'surprise', usually some cheap party favor like those little hand held puzzle games or a little snow globe or something stupid (but bc its NEW they will think its the most fantastic thing in the world!!)... i found that as long as each kid had their own bag of stuff to play with at their own will, we were generally okay. after one of your stops, have them trade a book, or some crayon colors, so those things last twice as long. on top of that, pack an emergency bag. this is YOUR bag. i usually carry bubbles, sidewalk chalk, tons of snacks (i dont know about your 2 year old, but sugarless bubble gum is a godsend)... anything that you can distract them with just in case of a meltdown... stuff for either in the car or to let them blow off some steam when you stop. GOOD LUCK!! you'll survive :)