I presume you have a HighLine system with the Harmon Kardon setup?
If so, option 1:
All of these items although will 'work' independently they all ultimately rely on the SatNav computer to run the whole shebang. Does the SatNav shut down correctly of it's own accord? (i.e. does the little little light go out once you open the boot and providing you open or close nothing else within 5 or so minutes?).
If not, option 2:
The water damage is more extensive than you think. I would try looking at the fuses at a minimum and maybe then look to see if there is members local to you who may be willing to help out in swapping components over with their own to eliminate any of your components as faulty.
More ideas may be forthcoming from other members too