We have that door in our ACE. Here is the info from someone who did an upgrade install:
Last year I was at my dealer looking at different trailers to get ideas and I came across a fantastic solution, in another cruiser RV product. It is made by Shower Enclosures of America. I got the Arcadia model, here are a few pics of installed in my Fun Finder 242BDS:
The result is stunning, it completely changed the feel of the bathroom and liberated floor space where the curtain used to bunch. My wife and kids actually gasped when they saw the difference.
The quality is incredible, each part is custom made for the application and works beautifully. One set of magnets clamps the door shut for showering and another one keeps it open when you are not using it.
The upper rail is curved to give you more shoulder room and the curtain itself is kept tight between the 2 rails so you don get stuck to it. It's an amazing balance of form and function.
Installation was easy but be sure to read the instructions over to understand them as some of the diagrams are not as clear as they could be.
It is only available directly from the the company and for a very affordable $110. To order you will need to call the company directly and speak to Traico. He was incredibly nice and helpful.
Be sure to measure the sill length and height of your surround. Not the wall height, but tub surround height. They have several different models depending on the size of your tub and surround.
Shower Enclosures America