Stop door leak
You probably just need to change the weather stripping. http://www.gmpartsnow.com/oem-part/chevrolet/monte-carlo- parts/2005/ls/3-4l-v6-gas/body-hardware/exterior-trim/upper-molding- left/10321351 for $81.36, or just pull it off a car at a junk yard if you want it cheaper.
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