A car's interior is a pretty awkward place to work. As soon as I freed the navigation LCD assembly from my 2004 Mazda RX-8 dashboard, I moved my project to a flat work area. It was lined with a clean soft white towel to reduce chances of something getting scratched up.

I immediately unclipped the center speaker mesh, because that looks extremely fragile. I set it aside in a safe out of the way location. In hindsight, I didn't need to bother. This large panel can be freed easily enough.

There are two buttons on this assembly, one on either side of the retracting hood and each secured with a screw. The retracting hood itself is an assembly I can unscrew as well.

The electromechanical assembly can then be separated from the large cosmetic panel.

I was encouraged by what I saw on the side. I can see the retraction gear mechanism and two details that would help me reassemble this later. First, the motor has a D-shaped shaft (round with a flat section) so the gear can be removed and reinstalled in the exact same place. Second, there is a small white mark on the gear for alignment with a similarly marked tooth on the track.

I also saw the retraction hinge is hollow, with a beefy ground wire through the hole on this side. This will help me route wires for my project. But all I see here is a solid grounding wire. Where is the wiring for everything else?

I found my answer after undoing the four screws (two on each side) holding the hinge in place, freeing the hood itself. Now I can clearly see a wide flat FPC (flexible printed circuit) handling the majority of electrical connections between the base and the hood. I can also access the two screws holding the hood lid.

Once hood lid was removed, I have a clear view of the retraction mechanism sitting behind the LCD screen. I would have expected the retraction mechanism to live in the base and not in the hood, but here it is taking up valuable volume inside. I also didn't expect it to be controlled by the LCD circuit board, but I learned this was the case from RX-8 owner forum of others who have done this before. I had originally thought I could just remove everything inside the hood but, if I want to maintain the hood retraction capability, I'd have to keep the LCD circuit board for its little side function.

Removing the motor assembly allowed me to open up the stout metal shield protecting the factory navigation LCD screen. This shield is the destination for that beefy ground wire I saw routed through the hinge. Using my multimeter, I found three of the FPC ribbon cable connections had continuity to the beefy ground wire, but they were apparently not enough. It sure looked like Mazda engineers were forced to install additional grounding during vehicle development. I wonder what the problem was.

Speaking of problems, this section of the LCD circuit board has me extremely worried. Based on CAUTION! HIGH VOLTAGE! warning printed on the circuit board, big beefy components nearby, and thick wires leading to the display, I deduced this is for a CFL (compact fluorescent) backlight. My car was apparently too old for a LED backlight.

A high voltage transformer like this assembly will throw off a lot of noisy electromagnetic signals, the kind that would mess up a capacitive touchscreen. The factory screen is not a touchscreen so it has no worries on that front, and the stout metal shielding would have mitigated interference with other components. But I'm going to swap out the screen and keep this circuit board to manage the retraction motor, and this circuit might be trouble.

And that's not my only trouble. After removing the factory LCD assembly, I measured its width at 177mm including the sheet metal cage. My wireless CarPlay/Android Auto receiver is wider at 190mm and would not fit in between mounting posts molded into the retracting hood.

In order for this to fit, I will have to cut something. RX-8 owners who posted their tablet installation procedures on the RX-8 forums usually cut these mounting posts. I hesitate to make destructive modifications to my car. I would much rather cut into the inexpensive receiver, because it would be much easier and cheaper to buy a replacement off Amazon if I make a mistake. But before I start cutting, I should look inside to see if there's anything critical along its edges.