It could be mildew. Thats why I suggested lysol, to kill the mildew. Or you can try what the other guy posted. It will take you a couple bucks and 5 minutes to try, if the smell returns, then take it to the dealer.
2011 Space Grey 135i Manual Coupe Sport
06 GTO , 06 WRX, 59 Bug, 03 Dakota R/T, 03 SV650