Chris, many thanks indeed for these additional tips.
I have duly noted the impressive work a number of members of this forum have done fabricating spark plug covers, but this kind of metal work is well beyond my ken (I'm not mechanical, own only a few tools, and don't have a garage).
I understand that it is possible to install Focus covers on the older Duratec engines, but that these will not fit on the GDI models.
A quick ChatGPT query (sorry, robots again...) suggests that there is something north of 2000 GDI-engined +4s out there. I hope that some industrious soul will see fit to make something available to us know-nothings!
In the meantime, I'm at least slipping some heat-resistant fabric over the engine when I wash the car.
