don't ever half ass niteshades. I did it with wet sand and all that and mine look fantastic. I also am an art student and had a friend who works at a paint shop supervise me.
I niteshaded my third brake light too. significantly darker I might add, but it all looks perfect. you just have to take your time for real man. lemme walk you through what I did.
wet sand tails (not the reverse parking light though, since i was not tinting that)
clean with alcohol.
mask off reverse light.
spray perimeter of tails, starting off the light and passing over
spray even a light even coat, starting off the light and passing over.
repeat until desired darkness.
don't worry about bubbles, they will disappear.
I let mine dry a few hours in front of a de-humidifier.
then I clear coated twice, then wet sanded again, then cleaned with alcohol again, compounded and then waxed.
also, you posted this in the engine performance section, so if you were expecting any horsepower gain, you'll probably be hugely disappointed....