Hi cobb,
If you look in the section for the 2006 FLHTCUSE or search for LED rear lighting you will find several threads on ideas to increase the rear lighting on the 2206 leather Tour Pac. Many of us ordered an LED light strip from Custom Dynamics that sticks on the pack just above the antennas. This is a good spot since it puts the light high up for tailgaters to see. There is an easy hookup electrically too. The threads have full instillation instructions and photos. You could also consider the saddlebag LED spoilers made by Harley. This puts lights farther out so those behind you can gauge the with of your bike. Then you could get an LED rear fendertip light kit to add even more light.
Motolights also makes rear LED lights that you could probably install as well. Then you could consider too getting a tail light modulator to flash you rear brake light when you are stopping to draw attention as well.
Here is a shot of my LED light bar on the Tour Pac, I used a clear lens with red bulbs but most ordered the bar with a red lens.