after 8 years of ownership (in mid michigan/northern indiana) my paint on the bottom of the doors where the seal hits the door was gone for most of it. i might have started getting a real light coast of surface rust but it never got close to rusting it out. just a point of reference. the door seals may have been knocking the rust off as fast as it could form due to the rubbing it always did? just a theory. as you said it would need primer/paint to fix it, but i would suspect it will occur again due to the seals.Looked on my drivers side front door on the inside where they pinch weld the outer to the inside there is 3 pieces of where the paint has flaked off to fix this would I need to primer and then touch up paint
I noticed just a small little section on my 2014 has a little paint flakage and there's a bit of rust so I'm going to work on that hopefully next weekend. I'll sand it down and probably hit it with primer and maybe just a bit of touchup paint. It's such a small spot, about half the size of a dime. But better to be proactive now rather than later.I've also heard of the bottom of the doors rusting - check the door bottoms - inside and out.