That's not bondo. It's seam sealer. This is used to ... well ... seal seams in the metal. It provides a seal as well as provides better structural support. This comes from the factory with the stuff on most cars. Every manufacturer uses it at their own pace, meaning, some use more and some use less.
EDIT:
There has been a few people who wondered if this is "actually" stock. I was watching a YouTube video today and found this. The vehicle in question (Dodge Charger SRT) has all of it's "guts" taken out. You can clearly see the seam sealer was put on after it was painted, and it is completely stock without any damage having been had.
