Yeah I drove my 2001 S-10 Xtreme until about 2007 when one too many parking barriers FINALLY put a split right down the bottom of the front airdam that they came with. This does seem like a poor quality part that might need to be recalled.
I will also mention that I did pull out of a parking lot where I rubbed slightly to form a 2 x 2 scrape in about the exact location where these cracks are on the underside and I didn't get the crack. I might perform that reinforcement job. I think I can manage that one.
This was after a repair using a J B Quick Weld type bumper stuff made by Bondo.
It was my first and so far only attempt at body work!! Jeez!
It didn't hold BTW. :