Sounds like a great idea, but I'm not sure I'd spend that much on it for non essential extra features.
You said the Xenarc would have the warranty still, so I assume that means that you don't have to open it. If thats the case, maybe producing an outer box that people can put thier monitors in might be better.
Take your ideas and figure out some different "levels" it could be produced on. What you have in the first post seems like a top of the line setup for the Xenarc. Instead, what if you made a box that was easy to fab into the dash and only had a cover that slides up and down? I'd buy it cause thats all I want. Next step up could be making one that is electric and slides at the push of a button. Next could be one that auto slides and has an amp, or maybe volume buttons.
So, in my opinion, two key points would be: Make it so people can use monitors they already have (even if you only make them for Xenarc, at least I could upgrade my system with your product) and start a little smaller then a full featured, top of the line model.
Good luck with your product. Look forward to it being developed.