Good point Rob. Many aftermarket lights don't provide for OEM license plate illumination. Below is one of several types available for Harleys with that clear section.
Rusty- consider one of the license plate mounted brake light supplement kits. I recently rode behind a BMW modified with a kit that have a light in each upper corner. They would rapidly flash two or three times then go on steady at each brake application. I don't know the manufacturer, but these were considerably brighter than the larger OEM stock incandescent tail light. Between the flash function grabbing my attention and the greater illumination, I noticed those lights before the stock tail light during daytime conditions. The small size of the installation did not detract from the bikes appearance one bit. Great combination for enhanced visibility.
Another possibility is LED replacement bulbs. For brake lights this can mean plug & play since the bases are available in 1156 or 1157. Turn signals may require a load equalizer because of the lower bulb current draw. The turn signal module may otherwise sense an inop bulb because the LED draw is less that what it's looking for. Brake lights don't have this function.
I've ordered an Adjure OEM HD Road King replacement tail light and flat led 1156? bulbs for my turn signal kit (red lensed turn signal/brake light combo). Also ordered are LED replacement units for the single incandescent bulbed forward and rear fender marker lights. Once all this is installed and evaluated, I'll probably convert the forward running light/turn signals and add the required load equalizer.
Here's a good primer on LED lighting:
As the above article cautions, the desired LEDs are of the newer super bright variety. Low cost LEDs may be of the inadequate brightness variety.
An example of the flat plate LED bulb: