In the final scene of "Death Proof," when the Dodge Challenger forces the Charger to spin out and crash, the Charger's rear wheels are still on the car. As the girls approach the car in the next scene, one rear wheel (driver's side) is no longer in the car.
In "Planet Terror", when the survivors are about to leave the Bone Shack, there is a lot of blood on El Wray's shirt, but when they stop outside for a brief moment in front of the Bone Shack, all the blood on his shirt disappears, and then when he pops open the trunk to Dakota's car, some blood reappears.
When Cherry Darling is riding in El Wray's wrecker before the crash, she is wearing a sleeveless red top. In the hospital when she wakes up and realizes she has lost her leg, she is wearing a gray t-shirt. When El Wray comes into her hospital room to save her, she is wearing the red top again. She tells El Wray she can't stand, and has been laying in bed with the sheet over her head, so she didn't get up and change her own shirt, and with the chaos in the hospital, it is unlikely a nurse stopped by to change her shirt either. (This goof may be intentional by the film-makers in keeping with the 'grindhouse' feel.)
During the car chase at the end of Death Proof, the cars are shown rubbing side by side at supposedly a high speed. However, two regulation cars of the road are shown passing the cars as they rub together, showing that was filmed at a much lower speed.
In the trailer for "Thanksgiving", the narrator establishes the setting as Massachusetts, USA. However, during the parade scene, several store signs and advertisements can briefly be seen that are written in Czech (The trailer was shot in the Czech Republic, where director Eli Roth was simultaneously filming Hostel: Part II).