oh, yeah i dont know the exact grit you need to get that smoothness for the tails, buti know its one of those higher digits.

Would it make the light look dull

USE 1500+ GRIT. WET SAND IT IN BETWEEN COATS, AND NOT AFTER THE LAST COAT.

yes, it needed to be in all caps.

Yah Im already done tinting and clear coating it. On my left tail light the clear coat dripped a bit. Could I use 1500 + gri to get it off without making it all scratchy and dull loking.

What do you do just tape off what you dont want painted and spray.

i personally would remove the tails...hit them with a 1500+ grit to get any imperfections out..clean with rubbing alcohol then spray a coat or two...wet sand with 2000, then spray my last coat