Aftermarket eyes free Siri button?

As we all know, a lot of new vehicles will be getting eyes free buttons in them. But what about those of us that don't have 2013 or newer cars?

Does anyone know of any plans for aftermarket bluetooth buttons that we can attach to our "old" cars? I know you can use a bluetooth headset to activate siri but I really don't want to buy one then tape it to my car.. That would be rather ugly.

If there isn't anything yet, I'm counting on you guys to make it happen for me! :)