You say it’s common but it didn’t used to be. It was common on Fords but no other vehicle manufacturer had it. Rear window heating, sure. But not front windscreen.
Moreover, Ford dealerships (in the U.K. at least) would boast that they owned the patent.
Looking online, I can see lots of references on car enthusiast sites talking about Ford owning the patent but any documents on the patent I find states it’s owned by an independent window manufacturer (like you suggested it would be).
So that leaves me wondering if either Ford had the patent but then sold it (unlikely in my opinion), or if they simply bought exclusively rights?
Moreover, Ford dealerships (in the U.K. at least) would boast that they owned the patent.
Looking online, I can see lots of references on car enthusiast sites talking about Ford owning the patent but any documents on the patent I find states it’s owned by an independent window manufacturer (like you suggested it would be).
So that leaves me wondering if either Ford had the patent but then sold it (unlikely in my opinion), or if they simply bought exclusively rights?