mach 460 amp plug ?

so i took my car to get my stereo installed, and for some reason the guy decides to cut off the amplifier plug that connects to the stock headunit amp, and then throws it away. any idea where i can find the plug that connects to the amp since i dont have a salvage yard around. thanks

ok, just to clarify this...you got an aftermarket head unit, and you need this plug for what? to put the old one back in? is this the wiring plugs that come from the dash that a wiring harness would plug into? is that the plug you mean? the wire to trigger the amps to turn on is blue or blue w/ white stripe