I dont see the need for INS Boxes on GT Cars, its a +1 rule to people not race.
INS Boxes started their usage in Europe due to heavy EFRA (equivalent to ROAR) regulations over Db noice levels.
And about their performance effect, i do feel that they take power off ... why to complicate this on a class that is looking for it place to grow ?
Jeff, your proposal on tyre traction sauces i think its a very good idea ...
cya !