GCS CS Style Rear F1 Fog / Brake Light

- 2015+ WRX / 2015+ STI




GCS now has an F1 CS style lamp for the 2015+ WRX / WRX STI. This also fits the 2013+ Crosstrek. Available in 4 different colors. NOTE: Please see main description for differences for this product vs the Subispeed F1.
OPTIONAL ADD-ON: Fog Light Wiring Splitter This product is optional, however it will allow you to connect your Rear Fog Light swiftly and effortlessly. For more details on this product, click here Plug and Play Harness This item will allow you to wire your new light without tapping the factory wires. This speeds up the install and allows you to return your vehicle to a completely stock setup. For more details on this product, click here
Reset Configuration
Red Lens with Chrome Reflector
Clear Lens with Red Reflector
Matte Black



Rear Fog Light / 4th Brake Light

USDM vehicles were not equipped with a rear fog light from the factory. They only have a plastic cap covering up the center of the rear bumper. No lamp, mounting bracket, mounting hardware, or wiring.

This GCS lamp includes the required parts to mount it to your USDM vehicle.

GCS CS Style Rear F1 vs SubiSpeed

The SubiSpeed rear fog light were built to our specifications for USDM vehicles. This means there is not a 7440 socket in the bottom and the brake / fog lights have a dual intensity function so that when run at night, the fog light is dimmer than the F1. This allows drivers to easily differentiate fog vs brake functions. However, this model sticks closely to the CS style rear fog lamp and is massed produced at a lower price point. Also note that the F1 function does not work when the fog light function is not in use*. There are various ways to wire this up that can change it into a solid brake light with no fog vs F1.

SubiSpeed's F1 light is produced in Taiwain, while GCS models are produced in China.

Seen in SS Rear Fog / Brake Light Overview

SubiSpeed Installation Video - Similar Model

Wiring notes for this model are below the video.


  • Smoked lens
  • Clear lens / Chrome reflector
  • Clear lens / Red reflector
  • Red lens


Red Wire - Brake Light Positive
Black Wire - Ground / Negative
Green - Running Light Positive

NOTE: Wiring for the Crosstrek can be routed directly to the tail light which has it's connectors on the OUTSIDE of the vehicle and not inside the cabin.

OPTIONAL Fog Light Wiring Splitter / Extension

If you want to wire this so that it only comes on with the fog lights you'll find yourself using a pretty long run of wire.

We've made a quick connect kit which will split the wires to the passenger side fog light. Just run the wire under the driver's side fender liner, into the vehicle, and along the door sills back to the trunk of the vehicle. The insulated connectors will be placed on the F1 light harness and extension. Just connect them together and you'll have a functioning rear fog light.

Includes splitter and extension with two pairs of connectors. The plug for the female end is not pre-attached so that the wires can easily be run through grommets in the firewall area. To purchase this addition, click here.

OPTIONAL Plug and Play Harness

This harness speeds up the install process. The stock wiring harness in the WRX / STI can be hard to crimp as the area is tight. Also owners who wish to return their setup to stock at any point and time can do so easily with this harness.

The harness has OEM style connectors on both ends which allows you to install this in-line with the factory wiring. 3 extensions allow you to connect the aftermarket fog / F1 lights.

  • Black - Ground (-) [connect to black wire on CS style lamp]
  • Red - Parking / Running Light (+) [connect to green wire on CS style lamp]
  • Yellow - Brake Light (+) [connect to red wire on CS style lamp]

To purchase this addition, click here.


  • F1 Style Fog Light Assembly
  • Mounting Hardware
  • Wiring Harness with Connectors
  • Fog Light Wiring Splitter / Extension (optional)


The bumper cover does not need to be removed in order to install this product. Simply undo the fasteners at the bottom of the bumper cover so you can gain enough access to knock out the factory plastic cap.

We highly recommend covering the lens of the new fog light casing with painter's tape or something similar during installation. This will prevent scratches while you maneuver it into position.

Our video will help your through the installation process, but please note the wires are different on this model vs the video. For reference, the OEM tail light wiring is as follows:

  • Black Wire - Negative aka Ground (wire to black wire on the new harness)
  • Brown Wire - Brake Light Positive (wire to red wire on the new harness)
  • Black Wire w/ White Stripe - Fog Light Positive (wire to green wire on the new harness)

If you use the fog light extension harness, the negative and fog light wires will be supplied by that harness. You will only use the OEM tail light harness for the brown wire (brake light positive).

You can wire the lamp as a solid brake light only. You would do this by connecting the fog light wire (green) on the lamp to the brown wire on the OEM brake light wire (brown). To make this only an F1 light and not run always at night, just connect the fog light wire (green) AND brake wire (red) to the brown wire on the OEM brake light wire (brown).

While many states allow brake lights that flash and then turn solid, some do not. Please refer to your local laws pertaining to this feature.

It is not required that you hook up the brake light wiring. You can run the product as a rear fog light only.

4 customer reviews

Average rating
(based on 4 reviews)
Ease of Installation
Fit / Quality
Overall Satisfaction
  1. Ok product

    By Rob May 24, 2019

    Bought this and the optional wire harness. Was easy to install. Lights worked for about 6 months. Then they started worked half the time. Now they dont work at all. Was kinda upset when they stopped working.

  2. Love this light

    By Anthony November 2, 2018

    Pretty easy to install. Love the look and the light function.


    By Dave May 22, 2018

    Easy to install, looks and works great! I lost one of the extra screws and Maddy sent me new ones out the next day thanks again Subispeed for all of your support!

  4. A+ Product

    By Steff September 17, 2017

    Really good fit and easy to install!! I'm very happy I purchased this item. Accents my car so well.

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