Ah, the family car trip. Often excruciating, frequently tedious, always unforgettable. For this third in the "Wimpy Kid" movie series, based on the wildly popular books by Jeff Kinney, the story moves from the schoolyard to the highway as Greg and the Heffley family leave home for his great-grandmother's birthday party. The kid actors from the first movie have grown up. Remember, one of the characters was played by Chloe Grace Moretz, recently in "Neighbors 2: Sorority Rising." And if that...