Here's my setup that I have been using for a few years now with great success. Amazing how many questions I get about these at car shows--no one seems to know what they are. The light is a bike light and in the strap niche is a kids toy ring that has multiple LEDs that sparkle--you really see my rear end at night!
I've got some bike lights on my pickup bed. Definitely helps, since the only other light on the back is the single taillight under the bed. Do you have any pictures in the dark, so we can see how bright they are?
Nice. Visible, removable and about where you'd expect to see them. Fits the bill to a T.
No pictures in the dark but I can assure you that the bike lights and the LEDs are quite dazzling for quite a distance.