Last years rule book doesnt say anything about paint, though I dont see that paint will stop fender damage from heat
21. EXHAUST SYSTEM: The header, muffler and gasket must remain within the stock dimensions, steel thickness, location and configurations of the original, as currently
delivered by U.S. Legend Cars International. The internal components of the header and muffler may not be altered. Stock U.S. Legend Cars International Borla and S&S exhaust systems (approved by INEX and delivered by U.S. Legend Cars International, Inc.) are mandatory. Header wrapping (tape) is acceptable. Ceramic coatings are not permitted.