If you want to retain the factory look n the roadster then install the TORS and TORS tune (dealer tune) or Dyno which is better, this will help as the catalytic converters are in the mufflers also a free flowing cross over pipe would help, while you are there take the header pipe off and remove the heat shields then send the header pipe away to be ceramic coated. When done reinstall increasing the gap in the heat shield between the header and sheild.
You will NEVER eliminate the heat but you can try to manage it.