So my 3906 body was all beat up and cracking. So I taped the big cracks and started spraying the inside of my body with this:

I know it's old, but hey it worked! Turned out great.

That was after the first coat, this is after 3:

You can see the little bit of overspray there was.

Tomorrow I am going to trim up the overspray and update this with pics of it on my truck.