Actually Richard and Dennis did beat the Cannonball Run record driving a Ferrari in 2008. Pete Brock had held the previous record in a Dodge Challenger.
I had a hand in designing and alteration of the Ferrari and am still associated with Gasmonkey Garage. You are correct in some things. Not everything is completely true
The f40 was purchased by Reggie Jackson but the work described as poorly done was completed by the Ferrari authorized shop in Garland Texas.
The Pontiacs actually were quite well done, but the sales price was not 650,000.
The time frame was accurate which normally isn't.
Jmho
Jay