[Jim Nilsen]

I filled my seams with seam sealer to make them flat as possible.

You can add extra sealer over the seam and let it setup for a week and then go back and trim it down flat to the surface or sculpt it in the corners of the tail panel and then epoxy over it. It can then be treated with primer and paint and will be good for as long as any seam sealer job would except it will look 10 x better. You do have to be able to let the car sit while it is shrinking down but I can't think of any car at that point that doesn't have a weeks worth of work to be before paint unless you wait to do the seems last.

When in the sun you can't see the seams on my car and it has to get really cool temp wise and be at the right angle to see the small amount of a seam shadow that shows.

You can also do the qtr to rear panel in the corners of the trunk lid area with the seam sealer the same way and it will be smooth and never crack.

I have had really good luck with this method and the seams could never be better looking or as invisible as they are.