Exterior vinyl and plastic maintenance?

[Iraqvet05]

We are in our 4th season with our 26BH and the exterior vinyl and plastic pieces are taking a beating from their years in the sun. The vinyl caps for the CATV connections will not stay on and the thin "strap" that holds the cap to the TT has broken. On the city water connection, the plastic leash/strap fell apart last season and most everything else plastic (outlet cover, light housings, etc) is looking a bit yellow.

On the vinyl U channel around the main door and storage doors, a spotty black funk has developed and I cannot get those clean with the car wash that normally removes black streaks from the siding.

Any suggestions?

[BigJohnD]

I really can't say how to fix it, but on ours, all the plastics get coated with the 303 Aerospace Protectant multiple times throughout the year. Never had an issue. But, most of our rigs haven't sat out in the elements year round either. Just our previous full time fifth wheel, and the present rig for 6-7 months or so. 303 works though.