It's called oil canning. There is an area in which the metal's molecules have shifted, crippeling the metal. If you know where to hit it with a body hammer or use a smoke wrench, you can shift the molecules back so that it doesn't oil can.

See the area that bends down at the edge of the crater? Somewhere along the area is/are the damage point(s).

I cannot tell a thing from the picture, and the description isn't much better.

A picture on the outside of the vehilce would help so that one can better read the metal. Also, does it stay kinked, or can you get it to release?