Yes this is the same I harness that I personally used on my 2000 GT with mach460 and can verify that it worked. Now my friend here says he tried that 70-5521 harness and it DID NOT work on his 99-00, hence he came to me askin what I had used, and I refered him to the metra 70-5511, which is the one in the link he posted. WORKED LIKE A CHARM. Im sure all this harness confusion has to do with the subtle changes that were made to the mach460 in 01 model years, but the above link contains the correct/proven to work harness for the 99-00. Granted there are other variations out there, some with gain controls on the speakers output signal, which would probably be useful if one chooses to purchase a ****TY radio with an even ****TIER EQ, but I have no idea of these work on our 99-00 cars, or the 01-04 for that matter.