Books are for the stopovers, yes? In the car reading can make people motion sick.
They certainly do this with me

Thanks for the suggestions ladies. Hadn't thought about sunscreen but yes definitely on my list now as is a torch and batteries.

Car games will be interesting as DD2 has no concept of ispy, everything starts with T! I have a blanket each and their own bottles (boosters have cup/bottle holders yay!) thinking about travel pillows but not sure if they will take up too much space