Sounds like a easy question yet where can you find blacked out or gray rear marker lights?

 

for real grey rear side markers, those are called Type-S side markers.

but if you can't afford or get your hands on it there's always these

http://www.uniquestyleracing.com/20actlclorsm.html

make sure you get the "Type-S Look" one and not the crystal clear one. i would imagine the clear one looking cheap and plasticy

 

i bought my rear type-s sidemarkers from ebay.
I bought the DEPO version

 

Does anyone know if there are any issues with the ones on ebay? Like fitment or the color not matching with the front side markers? I've been wanting to do this forever.