An audio system for installation in the tailgate of a pickup truck. A rugged, weather-resistant audio system is installed in a fold-down section of a multi-part tailgate. The system may operate independently of the sound system in the vehicle; the truck does not need to be running for the system to function. A low current draw allows the system to play for hours. The system may include a control that automatically powers off the system when the tailgate is returned to the closed position. The system may incorporate a USB port for device charging and flash memory playback, along with full Bluetooth streaming compatibility.