I have ordered an AT4 that will be built in July with the performance upgrade package. Will it have a Borla exhaust or a GM? I wasn’t given any options for which model of Borla it would be. I test drove one with that package and it was fairly quiet except when getting on it a little.
Test drove an AT4 yesterday with a 6.2 and performance package. Just barely louder than my current 2010 with a 6.2, 3.73 gears, stock exhaust, and K&N CAI. Couldn’t notice sound at all unless I punched it a little. It did seem a little more responsive to the throttle than mine. I went ahead and put my order in!