I saw a Mercury Sable one time that the exact same thing happened to. He hit a bulldozer that was parked on the side of the highway. He was passing cars on the shoulder and his intent was to cut back in traffic before he got to the bulldozer. Unfortunately, his timing was a little off and he hit the dozer at or above highway speed. The entire right half of the car was torn off and only the roof was intact. What a mess it was.
I've also seen several cars hit by trains and the largest pieces of those cars were the engine block and transmission. Everything else was thrown onto the flatbed by the wrecker drivers and scraped up with a front end loader.
Apparently the body was in just as bad shape, if not worse. Not much more than a greasy spot on the road.