How to create a single rotation whipping motion?
 

Hi I am a student designer doing a project for hasbro. I am working on an rc car that requires a special function that i'm not sure how to create. Most of the normal features such as foward/reverse motion and turning were easy to generate, but I'm having trouble finding what sort of motor to use to make a 360 degree whipping motion. I want to the motion to be button activated obviously, but the biggest problem I'm having is thinking of a way to make the whipping motion stop at exactly 360 degrees every time. Any suggestions or advice on what motor to use and how to achieve this function would be greatly appreciated.