The headrests in Chon and Ben's Jeep disappear are reappear several times depending on the scene. They are missing when Dennis gets in to talk with them. Later in the desert ambush scene, they have been replaced.
The goof items below may give away important plot points.
When Alex is going to be executed, O is being forced to watch by Sophia who is standing right behind her chair. In the next frontal shot of O, Sophia isn't there, but in the subsequent ones she is back.
When the hit-man disguised as a motorcycle cop comes up to the guy's car, after pulling him over, he has his hand on his holstered pistol. The pistol does not protrude through the bottom (barrel) - standard issue type. But, when the hit-man shoots the guy, there's a silencer on the barrel. There was no time to have screwed one on. However the hit-man has a holstered pistol on his right hip; he grabs the weapon that he uses to kill Frankie with his left hand from the back of his body.