Originally Posted by Dwight Frye

You should (A) tell the service manager at your local dealer that "irregardless" isn't a real word, and (B) spend the money for the harness and install it yourself.
It's about the cost of a few fast food meals and a couple of beers. Chalk it up to experience.

If you sell the car in the future, uninstall the harness, the original lock will remain in place (hopefully functional at that time) and you can give the harness to the new owner (with install instructions of course) and let them decide if they want the lock in place or bypassed.