Quote Originally Posted by Andy Bettencourt View Post
I would argue that it's simple logic.
"Logic" is not enforceable regulation. Your assumptions and expectations are not enforceable regulation. The words used in the regulations are the basis for the letter and enforcement of the regulations.

Show me where it says you CAN add this type of thing...
GCR 9.1.3.D.1.g, p404 Dec 2012: "Any exhaust header and exhaust system may be used"

See Rule #3:

How to Write a Rule

Exhaust heat shields attached to the car are not part of the exhaust system.
Incorrect. While it may not be part of the exhaust pipe, it is most decisively part of the exhaust system, for without that exhaust pipe there would be no need for the exhaust shield.

The rule states the system - not the exhaust piping as you are incorrectly assuming - is free. Thus it is.

GA