Hi cashcolt, inserts for tubs and shower stalls have been around for years. Here is one website for information, but there are others on Google

http://www.onlinetips.org/bathroom-s...shower-inserts

Edit: my url doesn't work well but you can still access information on it to show you the stall enclosures.

Ticks link failed to upload. Here's another link for a selection of enclosures: tub enclosures - Google Search
Good luck, Tom