When you are driving at night time and one head light (or fog light or parking light, etc) is out in a car you punch the celing of the car while yelling SPIDIDDLE!! The rest of the passengers in the car must remove an article of clothing, including the driver. If two lights are out it is then a "double diddle spididdle" and you must remove 2 articles of clothing. You must shout double diddle spididdle, or it is invalid.
NOTE: Clothing that comes in pairs, such as shoes, socks and the such are equal to one article of clothing. They can not be removed seperately.
Also, if you call a spididdle and you then see it is not one you (the person who falsely called it) must then remove an article of clothing.