Word Games for the Car

We took an extended trip this weekend and spent several hours driving back in the dark. Do you have any good (new) ideas for word games?

We tried:

Things you wear beginning with a particular letter
Words that begin with a particular sequence (like s-p-i)
Naming a famous person and then using the first or last name and using one of the names (or a rhyming name) for another famous person

In the past, we have exhausted all of the twenty questions, guess the animal, etc., games.

Thanks.