Speed trap prank

Step 3 Let the fun begin!

Roll down one of the front windows, point the hair dryer out the window and enjoy.  You can pivot the dryer to follow cars as they breeze by or lean out the window to make sure more cars see you.  Either way, drivers will panic and slam on the brakes.  If you're in a more obvious car (like a yellow beetle let's say) people will be even more confused and wonder what the local police department is thinking.