I'm interested in how the droid Razr knows to go into car mode in this dock because I prefer making my own custom car docks. With my OG it was easy to install a magnet into a generic $10 dock. The Razr dock costs $40 which is BS considering it is F-ing plastic. So if I can figure out how the Razr knows to go into car mode I can make my own dock for far less than what the OEM one costs. It's not a magnet in the part with the USB connector. I just ran a magnet along my phone where the USB/HDMI/Headphone jack is. Nothing happened. My concern is there is a pcb embedded in the car dock where the usb connector is that sends a special signal to the phone to let it know what kind of dock it is in.