My cousin just bought a tinting spray from Autozone or somewhere and took his off and sprayed them, however, I think he did it form the inside out but it looked damn good...Not quite as dark as the on in your pic but it looks nice...If you see him on he is VSpecPGT...Just ask him...He has a black 3rd gen and it looks killer...

 

sprayed from behind versus stock



again you can adjust how much you spray inside

 

thats looks good when done right (like above) .. it looks kinda cheap though when you go to dark, cuz then its like blackouts.

 

it come out better if u got a black tint out of a 3 stage paint system and cleared your tail lights. It wont give off that orange peel feel and look and look more normal. Plus it keeps ur rear lights from dulling out or u can do it to re give ur car that shine.

 

which does every one thinks looks better blacked out S4 tail lights with the back up light showing or the S5 tail lights blacked out with the back up light showing??