I had a similar thing happen, but to the driver's side. It ended up being the plastic piece where the light control knob is. It was a little loose and would keep hitting off the plastic piece next to it. I solved it by using a piece of double sided tape. But, it wasn't actually tape, more of a thin foam (still double sided). I put 2 strips in between the panel pieces and no more rattle. I got it at autozone. It is grey, which blended with the interior, and the peel area was red. This was a few years back, but that was my solution.
Current: 2009.5 SBM G8 GT, Premium Package, Sunroof, Pat G. ECM/TCM Tune, Roto-Fab 102mm CAI, LS7/LS3 MAF, Kooks 1 7/8" LT's, SOLO HFC's, SOLO Mach-Shorty Balanced Catback, SOLO 3.5" Tips, 19" Sport Package Wheels, GXP Steering Wheel, GXP Diffuser, Neondials, VG Sharkfin II, Debadged (Except Arrowheads), Hood-Vent Mod, Lower Grille Mod
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