TAG is a subject that doesn't come up very often these days. Diesel Power Products originally opened a mile from my house and I used to hang around there to kill time, Dave gave me some TAGs for testing when he was developing them. I may be able to scare up one in my garage. I still run one most the time.
As for the Scotty II noise you might pop your windshield wipers off and pull the plastic cover off and try adding some SoundMat or Dynamat to the cowl area, I heard that might help. I almost put a Scotty in my '01 back in the day but never could get the nerve up to cut a big hole into my cowl! Scott of Scotty intake fame is a friend of mine as well.
Also as a bit of Trivia, Scott is the one who came up with the BOMB acronym (Better Off Modified Baby!) but you don't see it expressed nearly as often as it was 15 years ago.
OK I guess I couldn't resist a quick walk down memory lane