Just thought someone might be interested in this wrench. It can be purchased through ebay from the seller "rooprict". Or, search for "sienna oil filter wrench". I purchased one and it fits perfectly. It is a quality product and is all metal construction. The seller seems to change the price and shipping terms, so I'd suggest watching his items for the cheapest combination.
I am not connected with the the seller, I just stumbled across a Prius forum where everyone was raving about it.