From the pictures it looks like the projection is focused on the film (also true for OP's link), where as in newer HUDs (such as my 2013 BMW) it looks like the

From the pictures it looks like the projection is focused on the film (also true for OP's link), where as in newer HUDs (such as my 2013 BMW) it looks like the projection has infinity set as the focus thus achieving the result of it looking like it's floating in a distance, and I don't need to adjust the focus of my eyes to look at the contents of the HUD. But I have not reviewed the tech spec, it just seems this way and the videos/pictures in OP's link and your link look way too jarring.