You can't really expect any 3" system to be quiet. Even with my 3" turbo-back its louder.
The Megan catback is not good imo. Loud and fits poorly. A 60mm WS2 with a resonator and cat should be quiet enough for your kid. Also like Louis said Dynamat in the trunk will keep the cabin noise down.
The Megan catback is not good imo. Loud and fits poorly. A 60mm WS2 with a resonator and cat should be quiet enough for your kid. Also like Louis said Dynamat in the trunk will keep the cabin noise down.