I added a Flowmaster muffler and K&N drop in air filter to my 2018 Trailhawk. Not too expensive and added a little sound. I think K&N also makes a CAI setup they claim is good for 9HP.
2018 JEEP COMPASS TRAILHAWK. KAR light bar with Cree lights, K&N drop in filter, Pirelli Scorpion AT's, Window Tint 20%, Flowmaster 40 Series Muffler.