I agree. If you do it right the first time with quaility parts there are no worries. Borla mufflers are built like a tank. The also have plenty of packing even though they have a straight through flow design. I would not build a 4cy or V-6 exhaust with just any muffler. I wish I could do the sound clip today but I am waiting for her to get here so we can leave on a trip and those sounds clips always take time.
I have heard several FSWERKS exhaust on 4cyl cars but they did not have one out yet with my set up.
Slight difference ya think.