Ok, going to go back to 80 talk. I bought a Garmin nuvi 1200 GPS a few weeks ago. It is the small size, I guess about 4x5" or so. I think it will fit either between the two center A/C vents or in front of the clock on the 80, and I will get a power cable and run it thru one of the vents or through the edge of the clock. I will have to figure out a way to mount the GPS cradle though. I could use an adhesive mount if I put it on the ledge in front of the clock, but I am leaning more toward something mounted between the vents.
I am also planning on adding some of those marine fuse boxes, maybe two 6 circuit boxes, one for always ON, and one for keyed ON.