Thanks Keith!
Our plant converted from block floor to cement. Some millwright decided they would be great firewood for his cabin up north. A few months later, the plant is in deep shit with the EPA. Turns out the blocks were leaching chromium and other nasties into one of Michigan's pristine rivers. Took a while to chase down the pile, and work it back to the plant. You can bet that they made sure those blocks were properly disposed of from then on!
I remember a purple short-bed truck coming down the line with a purple long-bed on it. Turns out the long bed truck with the short bed had come down the line about 20 minutes before. They blocked up the bed so it would go down the line and attached what they could, the rest went into the bed to be shorted out at the repair station.
Didn't happen often - there's not enough room to in the plant for that!
I'll add that much of this is discussed in JohnZ's article, including the difference between LOS and NOR front sheet metal.
http://www.camaros.org/assemblyprocess.shtml