Well, I think the fifth generation are actually laid out on a full frame chassis--the 4th gen have unibody constructed suspension in the rear, so the short answer, and it won't handle well.
Plus, that looks like a stock 2003 V6, and of course I don't mean to disrespect the six cylinder, but a stock V6 mustang isn't very exciting.
That said, the author doesn't give much info about the car, which makes me think my initial thoughts were correct.