He's wrong. It's on the outside of the tranny, passenger side. Tee'd into the fitting that the line to the cooler hooks up to. It's tight, but doable, especially if you let him have it long enough to have a good cold catalytic converter. He just doesn't want to do something that hard that's that cheap. Go ask the mitsu dealership if they have a flat rate time for the job. Bet it's 1/2 hour or less...

Not responsible for advice not taken...