HAS ANYONE REPLACED THEIR REAR SPEAKERS IN THEIR 1999 MUSTANG (THAT DOES NOT HAVE A MACH SYSTEM) WITH A MACH 460 SUB SYSTEM? IF SO I NEED TO KNOW WHERE SOME WIRES GO. I HAVE 1 -RED, 1 RED/WHITE, 1 - BLACK/WHITE AND 1 - BLACK/GRAY WIRES THAT I DON"T WHERE TO HOOK UP. THE SPEAKER WIRES PLUGGED RIGHT IN.