I dont think your setup is ever going to be considered to be quiet/drone free.

Its 3in, its not mean't to be quiet, its sized for people chasing power, and sound is the by product. (usually speaking)

Its a full setup starting from headers. Im my experience, catback alone are usually fine for sound needs. Once you add headers to the list it actually gets louder, like neighbors dobbing me in to EPA louder.

I dont even know what Im looking at in the pic you posted. You say its a single exit but there's an T intersection and im pretty sure in saying this, but that T intersection would not be an ideal way desgin an exhaust, its not flowing straight out.

If crusing around town in peace is goal, then stock car should be goals.