Nice to see another UK E36 here.
I like the idea of using the underside of the armrest for something, hadn't thought about that.
Not digging the sunglass thing though. I have mine (two as I wear prescription glasses as well) in the door pocket.
If you need any advice on putting a screen up top and moving the Ac, just let me know or have a look at my site or the tutorials at bmw-carputers.com