Looking for chapter book series to keep my 6-year-old entertained on a road trip

We’re doing a 2-week road trip this summer and I’m looking for a book series to keep my 6-year-old entertained instead of relying on electronics. He’s loved Diary of a Wimpy Kid, The Wild Robot, and Magic Tree House. He’s a pretty strong reader for his age and enjoys adventure, humor, and longer stories. Any [...]