The mirrors with indicators are standard on the Titanium/Ghia versions (after a certain production date) and ST versions of the Focus MK2. On these cars the indicators in the mirrors are controlled by the door modules (CANbus). Lower spec MK2 versions do not have door modules.
Door modules are only needed for the following options:
* Factory alarm with double locking.
* Comfort windows (4-electric windows with quick-up and quick-down functionality on all windows).
* Puddle lights in the side mirrors.
* Indicators in the side mirrors.
If your car already has one or more of the above mentioned options the car should have door modules. In this case the indicators can easily be installed and connected to the door modules. Afterwards it is nescessary to activate the indicators in the GEM module/fuse box.
If the car has no door modules it is also possible to retrofit the mirrors with indicators but is is a lot of work. To make the indicators in the mirrors work you have to install the wiring from the GEM module/fuse box to the doors. This may sound easy but it is a hell of a job because the doors needs to be removed to get the wiring through the rubber hose/connector on the body of the car.
My car did originally not have door modules so I had to install the wiring from the GEM module/fuse box to the doors. I converted my original electric powered and heated mirrors to mirrors with indicators using the original Titanium/Ghia mirror covers and indicator lights. It is not nescessary to change the complete mirrors if you want to retrofit the indicators.