OEM Roof Rack (9.67lbs): Front Rack Bar - 4 lbs 11.2 Oz
Rear Rack Bar - 4 lbs 15.5 Oz
AWD System: Chassis weight difference between FWD & AWD: ~ 137 lbs
OEM Head Unit Weights: 2006 XM/MP3 4.93 lbs (w/brackets)
2003 6 disc 4.57 lbs
OEM Navigation system: 7 lbs (as per 2010 chassis trim weight difference)
OEM Air Silence: 4.58lbs