A quick and discrete addition to any muffler, the whistle tip is welded inside the muffler to produce an ear drum piercing noise upon acceleration in a car. This noise can be heard for nearly a mile. A recent craze started on the sreets of Oakland by Bubb Rubb (see definition), often described an going "woo-woo."
it makes a screeching noise inside the eshaust pipes of a car.....the whistles go WOOOO, when you want a WooWoo, its a woowoo, ya know what im saayin, its just fo decorashon man just fo decorashon, thats it an thats all, the do it fo decorashon, but...its only in da monin, yo supposed to be cookin breakfast or somethin, so its like an alarm clock...WOOWOOOOO