89 345 LE Parting Strip/Ornamental side piece

[wimpy]

Spent several hours washing the wheels & outside & encountering lots of crud that seems to continue moving from behind this piece to the surface below it. There is some sort of partially deteriorated sealer visible which has allowed years of dirt & trash to accumulate & migrate to where the sealer is still intact.

After an hour of trying to find the name for the part (red arrow) in the attached photo, could someone tell me:
1. what it's called?
2. how is the gunk cleaned out?
3. should I remove it completely, clean, polish the MH, re-install the piece?
3. what do I use to seal the upper gap?

The gray paint (yellow arrow) is flaking with normal low pressure water applied. I think there was poor prep prior to painting. I plan on removing the remainder & polishing the area from the black strip up to the roof (where it hasn't been painted). How do I determine if I'm dealing with clearcoat in that area?

[bobmiller1]

The upper “Rub” rail has a plastic/vinyl insert that you can remove/replace/re-use. Once it’s removed you should be able to wash the track out completely. As far as the lower goes, I personally would repaint. I considered a wrap, but to hard to do the generator, water heater, and furnace outlets, paint would be a better choice, Regards, Bob

[Boom Sounds]

I think that lower section fails in high temps. Mine is all flaking off. Like Bob says, I reckon repaint