You can use white out, or finger nail polish. Its true what people say about muscle memory and ear. But, I taught myself by putting a couple dots of finger nail polish in the thumb position, then would practice moving my hand from different positions constantly landing on the dots, reinforcing the muscle memory, and the tone. Then would play eyes shut. I am not certainly the best in the world, but I can play the thumb position.
I am self taught, have had a few lessons. Bought books, taught myself site reading and the fingerboard.
Its true about the note not being in the same place all the time, check your string length from nut to bridge, your string height are some of the factors if the bridge is moved or the weather/humidity changes drastically.
Not everyone learns the same way, some are more visual. Why limit them based on your views on what "should" be?
Think of a keyboard for a computer. some have to use one finger and look down no matter how many years they have used it, others all fingers and thumbs not looking.
As far as the race car driver analogy, when your driving that fast, less distractions are better. I am sure they learned with full view.