When Illya shoots a dart at the voodoo doll with El Supremo's face on it, the closeup shot shows a red feathered circle around the dart covering the face. In the next split second wide-shot cut of El Supremo's side profile while holding the doll, the doll's face has no red on it.
The license plate on the taxi while it was being chased was a personal vehicle license, but after it crashed it was an actual taxi/commercial license plate.
During the opening sequence the plane landing is clearly a prop plane, but the sound of a jet plane can be heard.
Though this was supposed to be in Florida, the license plate on the taxi is a California plate.
At one point after the chase with the red car and the taxi, a studio light can be seen reflected in the rear side window of the red car.