Not surprisingly in a lot of searches no one seems to know how to update the Gracenote database. A call to Entune support, the woman I talked to seemed annoyed about me even asking and was surprised there is even an update button in the car for it. She just said to take it to a dealer.
Even more surprising is every other major car company using it has a link off the Gracenote site to the manufacturer for how to update it yourself. I think Toyota wants the dealers to do it as part of maintenance but since all of the dealers in my area don't seem to have a clue what it even is or know next to nothing about the different features of Entune (several didn't even know about new safety measures of the currently lineup of vehicles). It doesn't seem likely that the dealers will be updating this for you.
Here is a link to the Gracenote site for updates to non-Toyota vehicals.
http://support.gracenote.com/articles/P ... actUs&pn=1