Yes, I believe they are just over $100 on ebay, though I am not too keen on the effort required to thread the wiring through. I have reverse beepers and no towball, so don't see much need other than it would be cool to have. My main aim was to have usb, bluetooth and aux. The USB is awesome though it doesn't always let me scroll through the folder view, what's with that? Also, USB SEEK is a bit slow, moving only a few seconds back or forward at a time. Have you installed the camera?