I purchased a sheet of ABS plastic that is 3/16" thick and 32" wide by 48" long From "http://www.tapplastics.com/shop/product.php?pid=335" The sheet of ABS plastic shipped was ~$80.]
I should also mention this is for a 2010 XFE cobalt 5 speed and has no A/C. So you might have different clearances if you're gonna put your own in.
I was able to tap four holes on the frame so no drilling! I then used seven other zip ties that went threw existing holes and the cross bar under the radiator.
Where the skid plate and the air dam meet I plan on riveting some right angle plastic holders (similar in what you use for cheap book shelves) to help give the skid plate some support in the very front of it.
To tell you the truth I really haven't noticed a big difference in MPGs but it is nice to have something protect the radiator from things underneath. ex. rabbits, large ice chunks and road grime.
I'd also recommend trying to use as mush stainless steel or aluminum fittings so that you don't have to worry about much rustiness.
Last edited by Black; 01-01-2012 at 12:02 PM.