Just purchased my '07 Dbl Cab two weeks ago and within the first week my AM/FM/CD tuner became erratic and started shutting off and on whenever it felt like it. One time it came on and began playing the CD and was displaying random characters in the display. It would not shut off using the on/off button. I, too, resorted to the "cave man" act of tapping it with my fist and "whoa la!" it turned off. I took it in to the dealer and they confirmed an "internal malfunction" and had to order a new one. Just called today (9 days later) and they revealed that the radio is on backorder and I have to wait at least another week.
