Here is a Cardinal Skyline series sliding shower that recently became available.  This sleek enclosure is simple and elegant.  One side has a fixed panel; the other side slides along on bold rollers and a single rod.  It breaks all the rules of a traditional slider by doing away with both side rails, also the full length bottom track has been replaced by a small guide.  They managed to replace the top header by adding the lower center wheel which keeps the door from coming off the track.  Instead of a normal towel bar for a handle, now there is a 2 1/4″ recessed finger pull.  The Skyline series is available in both 3/8″ and 1/2″ thicknesses with a 90° return panel available in 3/8″( 1/2″ return coming soon).