One thing to keep in mind is the glare you might get up top in the bin so plan to recess it into the enclosure you design.
Why do you want to keep the factory radio? I ask because you're not using the lower din slot which is made for the 6 disc so an after market din unit will slide right in there.
Here's what I did
http://smg.photobucket.com/albums/v6...motu/CHILLIN2/
Mine is quite different but tshirts and fiberglass are your only real options but it might be easier to find an enclosure that you can modify or mold off of. The gauge pods in mine were bought on Ebay and then hacked
http://img.photobucket.com/albums/v6...tu/podleft.jpg
Another option for the sentra is to use a flip down monitor and ditch the sunglass holder and move roof button to where your mirror switch is.
There are a couple other Sentras on this board too but iirc they were flip up with the original lid on them.
Good luck, don't take as long as I did
