I can't recall ever seeing one in my online travels, which does not surprise me. This is not considered a normal consumable item, or even a long term wear and tear item. In my mind there are two choices, order it from the dealership, and be prepared to pay through the nose for it, or start calling salvage yards.

I'm just curious, how did the present one break? Seems like a pretty unusual thing to have fail, unless is was damaged in some way, like someone fell on it and it broke, that kind of thing.