It would depend on what you want in the end. It looks like the factory was content to leave this seam visible or they leaded over it.
If you want to hide the seam forever weld it or lead it. If you just put plastic, bondo, over it someday down the road it will show up....slightly, but you'll see it.
I know, I can hear it already, there are guys who are going to claim there is no shrinkage with plastic, that it just is not possible.
I did what you are attempting to do with a seem on a truck a few years back. I was doing a little custom work on this truck and wanted a cleaner look so I just filled over the seam with bondo and it looked great.
It took about three years and that seem I covered showed up.
I hate to use the word shrinkage, cause I guess that's not possible, but there it was, so call it whatever you would like.
I'm not saying it's big time visible, but in the right light at the right angle you see it.
Dan
