Continuity mistake: When Lori is shoved down the pipe, check out the close-ups as she slides down. At least twice she has one blue eye and one green eye - though her eyes are blue in every other scene.
Audio problem: When Rebecca is filling up her tank gun with beers, you hear her voice but her mouth doesn't move.
Continuity mistake: Lori had two stolen tanks to convert - a Russian T-55 and a PT-76. The outcome of this conversion is a M3 Stuart with a turret from something bigger - Sherman Firefly or M60. Better than McGyver.