The Kenwood KDC-BT645U has built-in Bluetooth. Unlike the Pioneer DEH-P4200UB, no adapter is required to sync this with your Bluetooth-ready device. This Kenwood car stereo does not have the thorough support system of the JVC KD-A615, but it is still one of the top three best in-dash receivers in our review. As our TopTenREVIEWS Silver Award winner, it has practically everything you could look for in a modern car receiver.
While this Kenwood car stereo has recommended power output of 22 watts, it can handle up to 50 watts of power per channel without overloading the circuitry or causing irreparable damage. It uses a MOSFET (or metal-oxide-semiconductor field-effect transistor) amplifier to give increased power output without overheating or excessive distortion.