I have a 02 v6 mustang and I enjoy the car but got the bug to get a biger engine and have more fun. I am very close to purchasing a donor car which is a 04 mach 1 which was rear ended and is a salvage car at this point and isn't worth fixing. The drive train and other parts like interior are much better then mine and a direct swap in. My question is with the engine swap. I am planing to pull off the donor car every piece that is needed including the wiring harness and the ecu. I am assuming that the ecu I bring over will have the vin of the old car, and that when I go for a smog check the vin numbers won't match my registration. How can I update the vin in the 04 ecu that will run the new engine so that it matches the vin of the hull?