Welcome to the forum.
I hope the OP found the answer he was seeking. As for you, the problem is due to A/C condensate and thus you may not be able to determine if yours has the problem.. I haven't been able to figure out why some vehicles are afflicted and others aren't. Anyway, the following is the TSB:
Date: September 27, 2010
Subject: Water Leak into Front and Rear Passenger Floor and/or Carpet Wet (Inspect White Plug in HVAC Evaporator Drain and Apply Sealer to Front of Dash Area)
2008-2010 Chevrolet Cobalt
2008-2011 Chevrolet HHR, Malibu
2008-2010 Pontiac G5
2008-2009 Pontiac G6
2008-2009 Saturn AURA
This bulletin is being revised to add the Pontiac G5 model. Please discard Corporate Bulletin Number 09-01-37-002C (Section 01 - HVAC).
Some customers may comment that the front and rear floor carpet is wet on the passenger side.
This condition may be caused by a plugged HVAC evaporator Drain. In some cases, water from the HVAC system will drain back though the front of the dash.
Note: Reposition of the heat shield is not necessary on a Cobalt and HHR.
1. Verify the customer's concern. If there is water on the passenger side front floor area, raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in SI.
2. Inspect the operation of the drain.
Note: Make sure that small debris is not plugging up the drain.
3. Reposition the heat shield (1) in order to gain access to the HVAC drain.
4. Remove the white plug (1) and assure there is no debris in the drain tube and/or plug. If debris exists, pull from the drain tube (do NOT force back into evaporator case) and reinstall the plug.
Important: Do not get sealer on the heat shield, on the end of, or within the drain tube.
5. Mask off the areas (1, 2) by the HVAC drain using high-quality automotive tape.
6. Apply high tech seam sealer, Kent Industries P/N P10200*, to the front of dash area as shown in figure below.
7. Remove the high quality automotive tape and reposition the heat shield to its normal position.
8. Lower the vehicle. Let the vehicle run with A/C on.
9. Perform a final inspection for the A/C and verify that the system is draining properly.
* We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources.
This product is currently available from Kent Industries (1-888-YES-KENT).
Part Number Description
P10200 HIGH - TECH CLEAR-SEAM SEALER