Whistle tips, also known as whistler tips, are a piece of metal installed into the exhaust pipe of a car in order to make a high pitched whistling noise. They are mostly popular in Oakland, California, USA, where they achieved notable reconigtion after a KRON-4 newscast that featured a hilarious man who identified himself only as Bubb Rubb who told cameras that "the whistles go woo woo". The newscast has become a legendary piece of internet humor and Bubb Rubb himself is arguably now more popular than the whistle tips that started it all. Whistle tips are now illegal in many North American municipalities.