re: BMW. They have narrow frames and no CVs and axles so there's lots of room for the hoses so its easy to copy what Ford did in 1965. Difference is that Ford had a wind tunnel and graphed all the drag and flow in the ducting.
Because of the stigma, I hate to suggest this group pay attention to NASCAR but; they have the biggest budgets in NA (hiring many F1 engineers), have 40 pretty competitive cars every one of 40 weeks, and all those cars see the same condition over one hundred times a race. That's a lot of data! Believe me here, they don't do what Ford did in '65. The last couple years have brought a lot of changes in what they do. The latest thinking is fans, fans and fans and cooling calipers first.
Running the hose to the eye is conventional thinking and AP suggests it in their literature. I started thinking about it when I got reports back from people unhappy with the results of using RooDucts and they all were using secondary hoses.
Personally, we don't use a hose and have had great results at all but one track. It has a lot of 3rd gear straights and 90s or 180s at the end of each one. We added fans to get more flow at slow speeds and there is no pad wear. The AP brakes last the whole tank instead of 4 laps.