Loo window Neuvo EK 2011

As it says above, the only thing we dislike about our Neuvo EK is the lack of a loo window. Has anyone fitted/or had fitted a window to this model? if so pro's/cons and costs would be really useful guys n gals. Any help/ advice would be good. 

I would not fit one in the shower part which just leaves over the loo. On my 2012 that is taken up with a cabinet which IMHO is much more useful than a window. We find that ventilation is sufficient from rooflight and that also gives enough daylight. I would be very concerned at the prospect of introducing the potential for leaks.