A friend of mine used the Night Shade on his black C5 Corvette. He had a friend blend the Night Shade in a 50/50 mix with clear coat. We applied it to all the rear and side lenses and it came out great. What were bright red brake lights and clear reverse lights now have an awesome "tint" to them. I can't speak for a Viper, but the Corvette brake lights are still highly visible during the day.
The way the lenses came out they still look more red than black. They are just a very dark red now, and the reverse lights look smoked. IMO, it was a great mod for the price and changed the character of his car.