Continuity mistake: In the scene where the passing truck blows Rango off the armadillo, he gets caught by a mud flap. (This is in the exact area where it was so hot, that the water from his glass dries up in seconds and his drink umbrella goes up in flames). But while he is stuck on the flap, he gets hit with a big juicy blast of watery mud off the road.
Continuity mistake: During the vending machine scene, besides the fact that he's hiding in slot D8, many of the slots are mislabeled. However, he is 2 positions in, so it would require $.50 to get him out, not $.25. And the slot on his right goes from having candy in the back, to having a different candy up front, then to being empty.