At one point I was going to experiment in making a
small mesh box that would fit under the headrest.
Just like the rangerover vents they are held in place by the force of the headrest pressing down on them. However, mesh alone would direct the heat directly onto your neck. Ideally what you want is something that is tilted and directs the hot air downwards slightly warming your shoulders and the upper area of the cabin.
I figured that, with a bit of an origami technique, you could shape the end of the pipe to achieve that effect and then just simply place it into the mesh box to create the airscarfs desired effect.
The pipe is the main thing of course and the rest is merely aesthetic camouflage. Finding the right one that doesn't impede the warm airflow is the rub.
Let us know how you get on and good luck in finding the right modded look to suit you. Because on a fresh, sunny, winters day these things do make a real difference when you want your roof down.
They're also very
HR Giger 'esque'
don't you think?