I have this same problem. I posted a video on the FB page. Mine rattles / buzzes at about the same RPMS you mentioned. Sounds like its coming from the right quarter panel as mentioned. I will be taking my car in to get this fixed as well, just need to find time to do so.
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Airaid CAI | Borla S-Type Catback | Amsoil 10w30 and MTG Trans. Fluid
382hp 387ft/lb | 1/4: 12.9 @ 112mph
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