I had to replace both of my '98 vintage Coleman Mach roof AC shrouds before our Thanksgiving trip. I had washed the roof and after "gently" sponging off the existing shrouds, they looked like this.
The replacements came in the form of new MaxAir AC shrouds for a couple of reasons.
1. They carry a 10 yr. unconditional replacement guarantee and a limited lifetime guarantee whereas the Coleman do not.
2. They are made of the same plastic as their vent cover brethren which are made out of a UV stable plastic polymer that resists cracking, tearing and embrittlement.
3. They were the same price at CW. I would have bought from RV Upgrades but I couldn't get them in time for the trip so CW had to suffice.
Here is one installed below.
I used the SS washers and plates but retained my factory SS screws as I didn't need the locknuts provided.
They look much better and should give many years of service...not that the originals didn't but you would think the factory would put better materials up on the roof considering its constant exposure to the elements.