Buck Sport Touring sells reflective stickers called Tailbrights that stick to the rear and side portions of the hard bags. Tonight I installed them. Installation was pretty simple; only had one or two bubbles on each of the stickers. I guess that you could make these yourself; but Buck Sport figured out the right shape, and I like to support companies that fill a niche like they do. The cool thing about them is that the stickers are black; so during the day you don’t even see them.
Here are some photos: