My Jeep is a bit noisy (re-done y-pipe, high flow cat, Flowmaster 70, all 3" pipe from the y-merge back). However, it's not terribly loud, and is reasonably quiet if I'm gentle on the throttle or at idle. I always try to be quiet coming in and out of my neighborhood, especially early mornings or late nights.

Fortunately, it's got a pretty smooth tone, so it's not too disturbing. Even my mom, who complains about pretty much any loud exhaust, doesn't mind the sound.
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1998 Jeep Grand Cherokee 5.9 Limited with Heads/Cam/Headers/Exhaust/Tune/Shift Kit/Suspension Work (178k miles, bought with 100k)
Rotella T6 @ 6k OCI