How to wash and wax/polish a Class C/fiberglass exterior

Thanks for all the help so far

I used to use NuFinish and wax the rv twice a year, but with my 39' diesel pusher it was a 2 day job and I was exhausted at the end of it. A friend who shows hot rods told me about Lucas Slick Mist that you spray on after washing the rv and dry with a soft cloth. I tried it and was amazed at the great shine it left, and it only took a few hours to get the whole coach done. I even use a Swiffer mop with a rag on it to polish the parts of the rv I cannot reach, so I don't even need to climb up a ladder. On my current rv, Winnebago Via at 26', I can wash and polish the whole rv in about 2 hours. I don't know how long the "coating" of Slick Mist would last, but I apply it every time I wash the rv, and cars at home, and they all look super shiny. It costs about $7 at Walmart and is in a blue bottle. Try it, you'll like it!

I use the marine Mequiar's 'one step' in the blue bottle and have used the 3m as mentioned , both work about the same as far as applying, buffing and lasting shine. I do the front a lot more often due to the amt of bugs which I have a lot of because I run the rig at night.
Placing a dryer sheet under the long extension cleaning brush when washing it dislodges the bugs when using any wash n wax car soap then top it off with the MEG or 3m cleaner waxes/restorer.

This process seems to keep the decals in check for a long time without destroying or fading them.

It sounds like the dealer put a Band-Aid on the problem. You need to remove the oxidation before you can get a good shine.

One method is the Zep/Red Max Pro Process. It's usually used on older RV's. If your rig came from Arizona it may be a good candidate for the process.

Many cringe at the idea of floor wax on their RV so, use the car/boat wax of your choice after you clean the fiberglass and remove the oxidation.
I'm sure other products work well. This method is effective and inexpensive. There will be labor involved but, any method will involve labor to remove the oxidation.
Try it on a small area before you do the entire RV.

It works well and gives a good shine to our 96 Southwind.
Preparation is the key to a good shine.

The dealer probably had some wipe-on stuff to make the rig look shiny on the lot. I had a guy come and detail my trailer 2 yrs ago and he used similar, but it doesn't last, and as you found out, looks worse once it's worn off.

Here is my thread about what I used....3M Marine Fiberglas Restorer and Wax.

The RV had a hazy film to it before we bought it. The dealership polished it up for us before we drove it off the lot. I think its got some sun damage because we got it in AZ. Anyway, it was super dirty when we got it back to Alaska and I pressure washed it with a cleaner that I guess was too harsh. I know not to get too close and to be careful of seals and caulking. I was able to get some shine back to it with a car polish and a buffer. Has anyone used Meguiars products? They are designed for marine/RV fiberglass. Thanks for the help so far.

1st washing by you?
Dealer might of used floor wax or detail wax, so it looked really great sitting on his lot?

NEVER EVER pressure wash an RV. Not only can as you discovered strip the wax. It can be far more damaging force high pressure water past seals and into or between the walls.
Get a long handled csr wash brush and a bottle of car wash soap. Wash starting at the top and work down. If its fiberglas exterior then products like McGuires RV/Marine products in the blue bottles. You have lots of boats jp there, stop in a boat store and ask them what they use. It takes time to do right.