Hey Matt, I now have my tag side mounted on the left side of the rear wheel. When I did have it mounted below the tail light, I fabricated a tag bracket out of ABS plastic that mounted to the 2 tabs hanging down under the sides of the rear fender. As for lighting, I drilled a couple of holes in the bottom of the tail light, and put Super Bright LED's pointing down at the tag. Even though I have removed everything, I can take a pic of the holes for the LED's if you need it.
Dave