Plot hole: Michael McKean quits pursuing Beldar and approximately 15 years pass as indicated by Connie growing up, yet when you see McKean again and his assistant, they have not aged at all.

Continuity: In the scene where Beldar has finished giving Gladys a driving lesson and they are sitting in the car, you can see that he has nothing on his lips. After Gladys kisses Beldar, you can see red lipstick. As the shots go from Beldar to Gladys and back, you can see the lipstick disappear and re-appear.

Continuity: In the scene where Beldar is "narfaling the garthok", you can see that Beldar has a clean cone. As he is pulling the garthok down after incapacitating it, you can still see a clean cone. After, when he is facing the high council, his cone is stained with blue blood. Where did it come from? He was not injured and you didn't see any blood coming from the monster.

Continuity: At the end when the girl sitting next to Beldar's wife keeps talking about great seats, you see she has pointy teeth, but at the end of that scene she has human teeth.

Continuity: After Connie and Ronny's first kiss, Mr. Conehead goes outside to talk to Ronny and it is completely dark outside. When he walks inside, however, it's really bright outside.

Visible crew/equipment: When the Alien ship is lifting the Coneheads in their red car, and the two Federal Agents, up with its magnetic gripper, as they get closer to the ship's lights you can see safety wires, either for the car or the two men.

Revealing: After Connie does the dive, when she gets out she is completely dry, yet she is wiping herself with a towel.

Continuity: When Beldar arrives back at Remulak and is talking to the leader, the orange thing in the guy's hands disappears.

Revealing: At the end when Beldar is back at Remulak and talking to the master, he makes that slave do a flip. In slow motion, you can see that it is a stuntman.

Revealing: The Subway sandwich that Connie stuffs all the way into her mouth is very cartoonish and fake looking.