What performance aftermarket muffler can I get for 2004 buick regal and do I have to get catback system or can I just replace muffler
you can put any muffler that will fit under there. any muffler shop can help. they don't make catback systems for your car. it was built to be a luxury car, not a hot rod. all a muffler will do is change sound. on that vehicle you won't get any performance benefit.
unless its a GS. Then it IS a performance car, and with the blower an exhaust will help exponentially.
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