stepside step painting?

[bark]

hello, I am almost ready for paint, my question is on painting the box, I was planning on painting the sides with the fenders and steps off, but remembered that there was drip check between the seams??? so do they all have this? or was it because mine has been painted once or twice before.
I could paint the sides, then install the fenders, steps, and seal, then paint it complete, but with all the angles there is a pretty good chance of getting a sag or run....

thanks!