Continuity mistake: While Major Allison is piloting the X-80, the style/model of the aircraft differs in shots, and two different numbers appear on its body - FC-226 and FE-229, as well as four different tail numbers that appear on its tailfin - 62216, 70236, 70229, and 61226.
Continuity mistake: When the Highway Patrol Officer hands the driver license back to Marion, in the interior shot he's holding it out with his right hand and Marion takes it with her left hand, but in the next exterior shot he's handing it to her with his left hand and Marion is taking it with her right hand. (00:15:50)
Continuity mistake: During the second round of drinks, the amount of ice left in the frozen daiquiri changes depending on the camera angle. It's poofy and opaque in the side view, and deflated and almost fully transparent in the tighter close-up on Shirley MacLaine, with an intermediate angle and state. (00:38:10)
Continuity mistake: The first time you see "No Sale" written in lipstick on a big mirror by Elizabeth Taylor, the "o" in "No" is partially formed. The next time you see the mirror, the letter "o" has been filled in and completed.