If one installs just the Cobb Ford Fiesta ST 2.5" Stainless Steel Dual Tip Cat-Back Exhaust and not the Ford Fiesta ST Catted Downpipe will you still get an awesome throaty sounding exhaust? Does adding the Ford Fiesta ST Catted Downpipe change the sound much at all or more performance oriented? Lastly are there any aftermarket exhaust that will actually pass California emissions? Thanks guys!