Think the post came from member not in uk,
I imagine auxillary heaters are market related as in colder climate countrys,
Uk petrol engines ive seen never have them, well ive never seen them , diesels I have and in electrical form and fuel fired.
Strange thinking of Ford, because the UK has a colder climate than The Netherlands. Weird that we do get a standard PTC heater on all the Ecoboost models.
Retrofitting should be possible, but it's a lot of work. You need to check if your heater box is compatible with a PTC heater. If it is, you need to remove you dashboard to place the heater element. After that you have to install the complete wiring loom and activate it with an IDS computer.
A lot of work