A trailer that still has its original shine can be maintained with wax. When I had a new
Casita I used Gel Gloss with great results for the three years I had it. I have also bought several old chalky trailers. No amount of waxing and buffing seemed to bring back a new-looking gloss. So I tried the Red Max Pro with very pleasing results on my ten year old
Bigfoot. I have not had any yellowing that I can detect after about 10 months.
As for cleaning, I also found out about Barkeepers Friend powder cleanser on the Red Max thread. I really swear by it for removing those hard to clean bug and tar splatters.