Di, I'm thinking about the many times we drove up and down I75 in Ohio to visit my folks and in-laws and what they did to help us keep the kids amused in the car for several hours.

A few things pop in mind:

An etch-a-sketch is good for a toddler, and not messy!!! One of my kids had one and it went everywhere in the car with us. Low tech, but I don't know if they even still sell those.

Small stuffed animals or soft dolls they can play with or cuddle with to nap in the car?

Big, thick kiddie books? Dan's 2-year old granddaughter has a number of those large print, thick, heavy pre-school books that she loves to look at in the car seat. I think they even have some that play sounds or words.

We sometimes go to the Dollar Stores or find small amusing things while out looking at garage sales for Dan's grandkids that are inexpensive and small when Dan has the kids.