When the GRX crashes in the Grand Prix, a few shots later, the remains of the car are gone.
Right at the beginning, the kid's hand keeps swapping from being on the middle of the paper to on the upper part, between shots.
In the scene where Racer X is attacking Cruncher Block's truck, at one point, you can see the level of the water in the piranha tank start to go down when the tank hasn't been shot yet.