Crushing

It's fairly common to see those car-carrier trucks full of new vehicles headed for car lots, but when I was driving home from DC a few months ago, and I saw a flatbed truck piled high with crushed cars. I thought it was odd, but I suppose there must be some reason to move crushed cars from place to place. What was really weird (and the reason I remember this three months later) was that I saw two similar trucks on the same drive. Was there like a crushed car clearing house? Has anyone ever seen this before? Odd.