At one point when Mark is buzzing Daria with the airplane she writes in the sand by the side of the road. Judging by the light and long shadows, it appears to be in late afternoon. Then Mark drops Daria something from the plane, which she runs to pick up, the light, and much shorter shadows, indicate that it is much earlier than the late afternoon of the previous shot.
(at around 58 mins) When the girl is having a joint, the image is flip-flopped as they talk. The audio and action are continuous, but the video is flopped and the boy is also seen lying down when he was sitting in the earlier shot.
When the plane is buzzing the car, power lines are to Daria's left except in one overhead shot when the lines are to her right.
When Mark is stealing the airplane in L.A., the shadow of the camera equipment mounted atop the engine compartment can be seen briefly as he makes a turn while taxiing.
Zabriskie Point, in Death Valley National Park (California, USA) is not actually the lowest-elevation point in the United States. That would be Badwater Basin, at a depth of 282 feet below sea level, which is also located in Death Valley National Park about 20 miles away.