PDI plugs found in glovebox

[tm1]

I found these rubber plugs the other day while cleaning out my glovebox. They have a notice to the PDI people to put these in some sort of crossmember extension, whatever that is. Does anyone know what these are used for and how important they are? I will bring these up at my next visit to the dealer, but my next oil change isn't due until Dec-Jan.

I have a 2009 matrix base model, got it last Nov so it's already seen one winter.

[keyboardracer]

Those holes are use to hold the car structure in place during assembly. You can craw down and it is roughly 2 inches in front of the trailing arms

I don't see an issue for rust or trapping water.. actually it might be better to let the condensate to drain out form the rocker panels.

[Hajoca]

The plugs are to cover the holes as mentioned above, the holes are also used for securing the car during shipping.