Continuity mistake: When the bird craps on Janet's windshield, it's at a certain level. When she arrives at the car wash, it's slightly higher up on her windshield.
Revealing mistake: In the first shot of the custom car shop, a nozzle can briefly be seen spraying showers of sparks (supposedly from welding).
Chosen answer: Actualy it says she should put it in neutral and keep her foot OFF the brake.