When Whitney wins the wrestling match, there is a shot from behind where she is obliviously wearing a top. A moment later on the reverse angle, she is back to being topless.
During the bus ride, the size of the school bus changes multiple times from the outside view.
In opening locker room scene, Samantha Stewart's character repeatedly takes her blue top off.
When driving to Florida for the Nationals, when asked how far the driver says 200 miles, but when the bus breaks down, the distance is now 500 miles.
During the incredibly brief hurricane, several shots show it raining quite heavily, but most don't show any water on the ground at all.
At the band competition finals in the final scene there is a mountain range in the background. There are no mountain ranges in Florida.
After traveling most of the way from Los Angeles to Florida (passing Vegas and New Orleans, amongst other places), the girls get in trouble and the LA skyline can be seen in most shots.