I thought everyone knew about this place, but I'll post the link anyway. It's a junkyard search engine, you enter your vehicle info ( make, model, year etc) tell it what part you need, and it searches the inventory of thousands of boneyards in the US, Canada and Mexico. You can narrow the search down to a radius from your home if you want.
Some of the yards don't update as often as they should, so if you find what you need almost all of them have a toll-free number. Call and make sure it's in stock.
Car-Part.com--Used Auto Parts Market