On the rear door (B pillar). This is really bad looking IMO. Unfortunately I park outside so it was bound to happen eventually. 2004 with 208k miles. Any ideas on how to fix?

 

Cheapest and best looking (for the $) would be to vinyl wrap it (very easy especially with a section like that). I'd vinyl wrap both pillars on each side so everything looks uniform. 3M vinyl wrap off amazon in gloss black is probably $20. Literally goes on like a sticker, just work the air bubbles out as you go (see youtube for help if needed).

Other alternatives: plasti dip, black touch up paint, body shop respray

 

Do you have to remove the pillar pieces before doing this? I just had the same problem actually and ordered a roll of piano black vinyl.

 

In this case, no you would not need to remove the pieces off the car (that likely wouldn't be easy or perhaps even possible). Here's basic steps (best to watch a youtube video).

Clean surface
Cut vinyl wrap so it is remotely the size (slightly larger on all sides)
Apply from top or bottom and smooth it out as you go (most amazon rolls come with an air bubble removal tool, but you could use something with a flat soft(ish) edge, or just your fingers)
Once it is applied and there are no bubbles, trim off the excess (carefully) with an x-acto knife or similar. Yes, in theory you will probably nick the glass or rubber trim on the edges, so don't do this on your brand new Ferrari

Sometimes using a hairdryer or heat gun helps get air bubbles out. Don't be afraid to peel back and re-apply as you go. A good 3M film is easy to work with and some of them even come with the clear wrap you remove when you're finally done. It's really easy, essentially you are just applying a sticker.