If he had a 2010 could have been this:
TSB Number: PIT-4904 NHTSA Number: 10032408 TSB Date: August 1, 2009 Date Added to File: March 17, 2010
Failing Component:
Parking Brake
Summary:
Chevrolet: water leak/carpet wet on the left front floor area. This may be caused by a gap or void in the seam sealer, in the cowl area on the left side of the vehicle.
Sure this will cause odors