I bought every harness that Year One listed for my car. The only thing I had to reuse was the radio harnesses and Rallye "light group" harnesses. Everything else is new.
The tail light bulb sockets were a little different then the original ones. The main alternator wiring insulator was a rubber piece instead of the stock hard plastic. And the insulation around the horn wires was different but other then that, they fit just fine.
I made sure to double check the connections and cross referenced the wires between the old and new harnesses. I hooked a battery up to the car last month and everything works.