Yes the screen dims and functions like stock. Brightness is manually adjustable for both the android OS and the stock unit. The android unit is within the screen itself, you just remove the stock unit, detach the screen from the box and attach the new android screen to it. Nothing under the dash otherwise needs to be changed.
Here come my other questions. Haha.
1. Would you be able to use stock USB ports on the android unit?
2. How does android unit AA compare to the stock system? Better widescreen supports without stretching?
3. When running the stock interface without filling up the whole screen, can you have another app on the right instead of the Mazda logo?
3. Any delay switching to the backup camera when you are on the android interface?
These should clean up my confusion. Thanks again!