I definitely want in on your secrets!
Send me a PM sometime.
Smoked would look really nice, especially on the black cars. In fact, see the picture of the prototype several posts up - the original SVX concept cars did indeed have smoked tail lights as well as all the lights in the front (including the fake center one) being smoked. Of course that probably couldn't make it to production legally. Kinda off topic, but don't Audi TT's have slightly smoked headlights?
As cool as it looks, I probably wouldn't smoke any of the lights (exception, 3rd LED brake light) unless there were a ton of bright LEDs in there. I don't want someone running into me!
A random observation I made on my way home yesterday:
A newer BMW 3 series signalled and pulled in front of me - the rear turn signal was red, and the light output of the signal was red too. No amber.
I'm sure there are several others, that was just the first one I specficially noticed since I've been thinking of this.