Looking for

of each different factory head unit:
- Entire front of HU (with all printing readable)
- Entire rear of HU (with all harnesses disconnected and out of view, all sockets clearly visible)
- Entire top or bottom of HU (side with manufacturer's label, with everything clearly legible. If you're paranoid, you can hide the last few digits of the S/N)
- A look into the dash opening, showing all of the harness and antenna plugs as clearly as possible.
Pictures should be well-lit, in focus, and large enough to make out all of the details.
Be sure to give your car's model and year, and the HU's model number (printed on the front).
If you're not ready to pull your HU and can only post a picture of the front, please do -- that's still better than nothing.