Pick up a clip-board that opens for storage. Add paper, pencils, crayons*, markers, coloring pages, puzzle pages, stickers, etc..
You can even personalize the outside with stickers, paint or paint markers. I like to personalize the back of the clipboard, so the work area is free of bumps. This is great for long drives to keep kids entertained.
This is also great for doing homework. When you really think about it – sometimes kids are in the car for a long time between school and activities of their own or their siblings’, they could be getting homework done. This provides a hard surface for doing just that.
*Just remember to bring the clip-board into the house so the crayons don’t melt in the summer heat.