An original, but still great! It doesn’t require any prep work and little to no adult interaction (if you have more than one child).
There are several great license plate games including the 50 states version and "make a phrase".
Would you rather questions are fun for any age, but it's entertaining to hear kids answer them.
A scavenger hunt does take a little bit of prep work, but it can be as simple as printing off a free printable road trip scavenger hunt.
A staring contest is probably the most straightforward game on the list. Although, the driver shouldn't participate.
This game is also called storytime. Have one person start with "once upon a time…" and have them add one or two sentences to the story.
If your kids or family members are into cars, try to spot at least one of every car make.