Alright, here's the second edition concept!

More notes, for your enjoyment.
-The colour will actually be black. The grey is for clarity.
-I have no idea of scale because I don't have a ZN40 yet.
Top:
-grey thing on the left is a headphone jack
-a few vents, for exhausting
-the middle thingy is a poorly drawn out of scale cart slot
Front:
-left row of stuff- control stick, Dpad, speaker holes
-I'm considering a SNES d-pad.
-The four tiny buttons are for screen control.
-The YAP64 jewel will also be a power light. It will glow blue.
-The mini-stick on the right is for "FPS mode", which I've explained a few posts above.
-I have no idea what stick to use. PSP disc? Cut-down c-stick?
Back:
-I may extend the button thingies into grips, but probably not. Then again it will give me more clearance.
-There is an L button, R button, and two duplicate Z buttons.
-circle thing=cooling vent
-the thing below the vent is a raised section for expansion pack clearance
Bottom:
-The thing on the far left is the power jack.
-Left row of switches: screen power, console power, FPS mode
-more vents in the middle, I'll probably leave them out
-LOB64 port and switch, which will either be master/slave or external/internal P1.
A few new questions:
1. What's good wire? I've heard that ribbon cable actually sucks. I've heard that controller cable is good. I'll probably use my own discretion here. But I need a list of stuff to avoid at all costs!
2. I think I need TWO TI cards, one for the console (obviously) but one to make a car adaptor as well.