See the propellers? The sound effects people didn't. They put the sound of a jet plane in there.

 

It turned out they got the DEFCON order backwards. Peace is actually "1" and war is "5". The filmmakers can't really be blamed though - it was still top secret at the time.

 

"Hey! Let's just take that other Jeep!"   "No! It'll be more dramatic if we run all the way!"

 

"I told you we shouldn't have bought those surplus Star Trek computers!"