Always the mad modder, I thought some of my fellow Volt owners would be interested in seeing the results of my final LED mod to the rear running lamps and brake lights. I added LED strips to the rear running lamps as well as an LED strip that follows the contour of the the rear hatch glass (don't ask me how I did that -- it was a nightmare before I got it right and I wasted about 4 LED strips in the attempt). Both are wired so that they turn on when the car's auto sensor switches on the headlamps and running lights, and both switch to full brightness when the brakes are applied.
Here are a few photos with the LEDs switched on, the first in running lamp mode, the second with the brakes applied. The latter photo doesn't capture the intense brightness of the LEDs when the brakes are on, but I can promise that no one behind me will fail to notice a brake application