I've seen '02-'04 Acura RSX with the rear fog light installed. To date, I have not seen an '05-'06 Acura RSX with the rear fog light installed. So, if you're wondering what it looks like on an '05+ RSX, click on the following image for an enlarged version:

I decided to install the rear fog light because I drive through the desert and central California quite often. Depending on the time of the year, the central coast get insanely foggy (especially during the summer). I've almost rear ended a silver Miata because the fog was so dense up north. Since I'm traveling further past the central coast in 1 week (past Klamath, CA), and it is currently rainy and foggy season in that region, this mod was executed at just the right time.

To kick the mod up a notch, I've added a rear fog light indicator light; basically adding an additional SMD LED into the cavity of the gauge cluster where the high beam LED sits. When I have my rear fog lights on, the high beam indicator will light up yellow, wired so that the rear fog light can only be turned on if the head lights are turned on (just like OEM front fog lights). The whole setup is controlled using gslowr's '07-'08 Honda Fit Sport combination switch DIY guide:

A modified after market OEM-style fog light wiring harness as the main wiring harness:

An extra rear license plate light sub-wire with male and female bullet terminals crimped on and routed through the 28mm hole plug on the rear firewall for an extra clean, OEM-style install:

Complete DIY guide will be available after January 4th. I'll be away for the holiday, but will continue to post trip-related entries until then.

Here's a video of the rear fog light in operation:

Any questions, feel free to comment.