What was supposed to be ridiculous about tfatf is the crappy production in it, the cast + production knew nothing about cars because dom's line, double-clutchin and not granny shiftin when your supposed to is idiotic, double clutching and granny shifting are the same thing! btw I had no idea trucks use double clutching techniques. I do know "Double-clutching is the proper way to downshift at speed without placing excessive wear on the transmission's synchronizers. This allows you to select a much lower gear without the tell-tale lurch you normally get when the clutch is let out after downshifting." as you can read here...
http://www.driversedge.com/dblcltch.htm now if your racing anywhere other than a straight line, double clutching is a great technique, because you want to downshift around the turns without wrecking your tranny.