I know this thread is pretty old, but this may really help a few others out there.
I have the 2011 X23J Expandable Hybrid camper and the shower curtain is(or should I say "was") the stupid plastic curved non-removable curtain.
I went to www.curtain-tracks.com
and looked at the bendable aluminum tracks.
Total for materials (for the track) was approx $25, however shipping was also $25
But we can no use any regular shower curtain and is removable for cleaning....