Common.. my 06 was worse than my 07 GXP, but still present. Higher rpm s and warmer temp eliminate the problem..
what to say... what to say..
2007 GXP mysterious (sold.. I sorry)
leather, monsoon, 6 CD, headliner, sport pedals, polished aluminum, custom front grille, GMPP stage II upgrade, GMPP exhaust, K&N drop-in, stubby antenna, Kappashield, XM, no front plate (2 tix so far)
2006 mysterious # 5330 (SOLD)
NASSOA # 87