If you really don't mind paying, try a different Best Buy. There are some around me that will do a little custom work, and some that won't. I think it depends on how much trust they have in their installers and if they want to take that risk or not.
Here is one someone did recently.
And if I'm not mistaken there was a kit on Ebay at one time. I don't know if it is still on there but I remember seeing it when I was thinking about doing a double din.