I have a 11' sunseeker 2450. It came with the horrible glass door on tracks, broken when I received it, replaced, and died again. Tried the extend a shower, didn't like how flimsy it was. If others are like mine, there's almost no where to hang towels too. I recently found the aluminum shower rod in brushed finished on amazon for about $50. It was made to fit 45 to 72 inch openings, my shower is about 35 wide. Because of the design of it, it was easy to take out about 13 inches off each of the four bars, and made it fit perfectly. Good design, it's very solid and looks nice, plus I now can hang towels! Here's a pic of it and the link. Enjoy.
Zenna Home 35604BN, NeverRust Aluminum Double Curved Shower Curtain Rod, 45 to 72-Inch, Brushed Nickel
https://www.amazon.com/dp/B00NXZQK12..._3QzTvb3PRRRW4