Abstract: An adapter for installing an aftermarket audio device in a vehicle. The adapter includes a first and second connectors electrically connected together, the first connector being suitable for connecting to a wiring harness in the vehicle and the second connector being unsuitable for connection to the wiring harness in the vehicle, the second connector being further suitable for connection in a different wiring harness in a different vehicle. The adapter also includes a plurality of wires electrically connected to the first and second connectors, the wires being adapted to connect to the aftermarket audio device.