I'm going to go against everyone here, but honestly. If the smoked tailights matches the theme of your car, then it will look good. For example, a blacked out car with a smoked taillights fits the trend.
But if you have a white M with brushed steel rims, and you throw on smoked taillights, that might look a bit off.
I'll post a pic of my e90 with smoked tails, and people are free to bash as much as they want