In the article feature of his Mustang it lists an Autopower Rollbar.
Probably the first one on the Autopower Page:
http://www.autopowerindustries.com/rollbars.asp
The "Street Roll Bar"
Or perhaps the "STREET-SPORT ROLL BAR" as they say designed for street use.
Since he lists harnesses in his description, the street-sport would give him attachment points.
Notice how TINY the base plates are! Real strong guys.
Nothing to bolt to the side sills for strength either.
And! the main hoop (er, only hoop) is PRE-BENT for you! I am sure the side bends are to give more interior room for the seats but I can just see those as the weak points that allowed the bar to bend as it was punching through the floor.
Scary "Roll Bar" in any case. Don't trust your head to this!