Newest one (looks much better in person):
I wanted to see for myself the actual size, and aspect ratio of the screen, as I want my images to fill the screen to the usable edges. I took out my tailor's tape to actually measure the screen. I put up one of the blue screens so I could see the edges of the image. The glass over the screen is tilted so measurements are as close as I could eye-ball without removing the glass. The available screen image is 11cm x 6 cm.
So any image I use has to be re-aspect ratioed to 11 x 6, in whatever size the image happens to be.
For instance, the above image started as 1930 x 1200. I opened it in PSP and resized it down to 1920 x 1047, which is 11 x 6.
Now, because the image doesn't need to be so big for the small imid screen, I down sized it to 500 x 273, which is still 11 x 6. Making the image smaller allows it to upload and save faster with no visible loss in sharpness or quality, again, because of the small size of the imid screen.
Then I tranferred it to a flash drive, plugged it into the car, and followed the screens.