Continuity mistake: When at the Men's Association, Mike Wellington raises a glass and toasts Stepford. He does this with his left hand. When the shot changes to show all the men, he is still doing it with his left hand. But when the shot changes back to Mike, the glass is now in his right hand, with no time between shots to change hands.
Visible crew/equipment: When Walter is driving down the highway with his family in tow, right after he explains to his kids why they're moving, he looks over at Joe with her head slumped against the window, and the reflection of some filming equipment (possibly the camera) is seen on the window at the bottom-right corner of the screen.
Audio problem: When Joanna goes to The Simply Stepford Day Spa, Clair begins her Clairobics, and says, "Come on Joanna." Behind Joanna, Clair's reflection shows her telling everyone to do the "spin cycle" but she isn't heard. Then in the shot facing Clair, she again tells them to do the spin cycle.