2014 - 2017 Vehicles have oval openings in rear valance. 2018 - 2024 Vehicles have rectangle openings. This 2.25 diameter BORLA system features 4.25 x 3.5 oval polished T - 304 stainless steel tips. It delivers the classic S - Type sound level with no drone inside the vehicle. BORLA Cat - Back Axle - Back exhaust systems feature patented straight - through and multi - core technology designed to unleash hidden horsepower. Increased exhaust velocity adds power, driving excitement, fuel economy, and the distinctive BORLA Sound of Power respected by motoring enthusiasts everywhere. Each system is built from premium T - 304 stainless steel, superior to T - 400 series knockoffs (such as 409), to give you the absolute best in performance and durability. Ultra - smooth mandrel bends ensure maximum flow power, and precision computer numerical control (CNC) manufacturing ensures an accurate fit. Best of all, BORLA stands behind every system with a Million - Mile Warranty. Just what youd expect from the worlds most experienced (and most winning) exhaust brand.