The Fiat 500's stock exhaust actually sounds nice too, like a very growly and aggressive 4-banger almost on-par with a Subaru boxer sound (but not too much like a lawnmower).
My Cobalt SS Turbo from the factory has cats, a resonator, and a "muffler" which is a box with a straight tube inside (non-perforated). It idles like a Japanese sport bike, but is very docile at WOT. I heard people that removed the resonator and muffler on the Cobalt LNF and it caused it to sound like a ricer, so I never touched the exhaust on it.
Bro any Subarus I’ve ever heard sound like ass and I live in Colorado, land of Subarus. 😂