I ordered the Rousch Axle Back Exhaust 1 week after I ordered my 2013 Mustang Gt Premium. The package arrived before the car...when my car finally came in, my husband installed the exhaust on day 2 of ownership (he said it was an easy installation, although he is a mechanic). I must say I am very pleased with the sound. My GT now sounds like it should. I get alot of looks with the great sound of the exhaust and a hot car. I would definately recommend these to everyone. It is not overly aggressive, but gets the point across.