make a keyhole camera look good and aim right is worth it? The license plate recessed illumination area has plenty of space. Would be pretty easy to exploit in that location and still look relatively stealthy. There are a number of wired camera choices which should work well.
Another option is a wireless license plate bracket with built in camera - no custom work needed other than getting power to the camera via the license plates lights or other power source. I'm not a big fan of the license plate camera look, but it's fairly easy to do.