Just added Magnaflow catback systems. Nosiy enough but not obnoxious. Adding the new K&N aircharger system tomorrow. I am definitely enjoying this truck. I am a Truck Manager at a large midatlantic Chevy store and was tired of selling these to others for them to come back with big smiles. No I am having fun myself. Tinted front window 17% and rears on back with 5% (don't recommend you cant see a damn thing). Has anyone tries the K&n sys yet?