A car stereo adapted to be mounted in a vehicle includes a front surface having an I/O port that facilitates communication with an external portable music player using a wired connection. Audio signals generated by the portable music player are transmitted without noise or interference via the wired connection to the car stereo. The I/O port may also transmit control signals from the car stereo to the portable music player via the wired connection. For some embodiments, the car stereo's I/O port provides power to the portable music player via the wired connection. For one embodiment, the car stereo includes circuitry to convert audio signals generated by an integrated audio source such as a radio receiver into a digital file format capable of being stored in the portable music player.