With the 4D display mocked up (roughly), it was clear there would be some interference inside the display case.  For the first prototype, it'll be slightly wide due to the control board, and now it's about 2 mm taller to take the display's PCB bezel into account.  (NOTE: The 3D model I designed of the OLED-128-G2 for prototyping is now available to the community in the TinkerCAD Gallery as well.)

The "cutaway" (actually the "hole" option) of TinkerCAD is very useful for seeing inside enclosed spaces.

It's also handy for measuring where to put features like micro-SD card slots.

While most of these models are white because it helps to have as much brightness and contrast as possible during on-screen designing, the finished product will most likely be black - (but a huge number of color options are available in ABS filament, and plastic paint would make the options virtually limitless).

I'm also making big changes to the power supply, to make it even more robust in light of the vagaries of car-supplied power.  The main capacitor is being super-sized to a 63V-capable unit that can withstand load dumps from the alternator, but which at a size larger than a typical C-battery requires a lot more room in the enclosure, and doesn't leave much room for anything else - so the enclosure is now expanded, and the capacitor has to come off the board and be wired to it, with a mounting method similar to that shown.  The middle capacitor is also being changed to *lower* its voltage in line with the original project instructions in "Practical Arduino", to minimize ESR (equivalent series resistance).

With these changes, the revision number of the project file increments to 0.3x and the Mouser projects have been updated to reflect the component changes.  There are no wiring changes so the 0.2x PCB project on OSH Park remains applicable.