That cupholder was made by a company called Sport Car Solutions, which is now Roadster Solutions. They no longer make it and considering they sold so few, I have never seen one for sale and doubt any will ever be for sale used, so don't get you hopes up. I tried emailing the company to see if the still had one somewhere, but they didn't.
I settled for the Ultimate Cupholder, and can vouch for it being a great solution.
