I hear you. Even my dealer doesn't have it. That's why I said that many dealers don't know about it.
Go to www.lexus-parts.com and look it up, or search for "gx470 cargo" on ebay. It does say Lexus on it, but like I said, I went to check it out and didn't like it, which is a shame, because I really wanted it (I'm a sucker for all accessories that say Lexus on them).
Here's an excerpt of an email reply from a parts manager, dated 6/29/05:
Yes, this new mat was release approximately 4 weeks ago to all Lexus Dealers. I can only imagine some dealers have yet to change there inventory since I'm sure most of them have an existing stock of WeatherTech mats. The new mat is very nice as it gives you the option to have the 3rd row seating with the cutouts or not. And best of all, it has the Lexus logo on the mat!