Not since Calvin relieving himself on your least favorite car brand has been so easy for a driver to show his/her feelings. "The Hand" remote controller window sign is a funny and useful gadget that signs how you feel towards the other drivers. For $40, this electroluminescent gesturing hand will allow to focus your attention completely on the road.
Just make sure you always have some expression always on. To correctly fit all the different gestures, the blank hand has six fingers.