Aftermarket Radio Wiring Harness (70-5600) by Metra, with OEM Plug and Amplifier Integration. For aftermarket stereo. Metra preassembled wiring harnesses can make your car stereo installation seamless, or at least a lot simpler. With precrimped ends and prepopulated connectors, your wiring task will be highly simplified. These harness connectors will mate with your components exactly like the OEM connectors.