guys, all you had to do was route the 2 wires: (positive & negative) from the rear foglight to the front (under the car, the same way a towing kit would be) and then wire in a 4 pin relay to the foglights that are up-front. you dont need an expensive relay & button. this way your foglight switch on the steering wheel would control the rear foglight as well as the front ones.
The problem with this setup is you can't control when to turn on the rear fog light.
There is a reason why it's called a fog light. It's to be used when there is fog or during low visibility situations (heavy rain or snow). When you drive in great weather and the car you follow has it turned on, it's simply blinding and annoying so having control of this light is a good option. I spent the first part of my life in Europe where all cars are equipped and a lot of drivers simply misuse it.
Yes it's more expensive since you need to get a specific harness but it's also more respectful of other drivers following you. Used in the right conditions, it's perfect, it allows you to see the vehicle in front of you much sooner. Used for no reason at all, not so useful.
Just the way I feel about this fog light since I have been confronted to this kind of situation so many times. I am not sure why this is not a requirement in the US. German cars made for the American market still have it.