[Bru]

Try a eBay or Google search. The part number is 6788114110
I saw a new one on eBay for $84. Before you buy a new one see if your old one can be mended.
Also, use Amour All or Toyota vinyl and leather protectant on the contact surfaces to repel water. Check your tail lights for water inside. That is another point of entry. I keep the rubber plug under the spare tire slightly open and taped down to allow water to escape from past experience. I also keep some paper or micro fiber towel under the tail lights to catch any water the seeps in. Check it after a rain and squeeze out the water if its wet. It keeps water away from the tire well.