One of my previous cars was notorious for having the instruments reflecting in the windscreen and I can tell you it was blinking annoying - I suspect you might find a proper 'heads up' display equally irritating once the novelty wore off.
I can't imagine any conceivable reason for wanting to have your pedal and steering inputs displayed on the windscreen. You already know what you're doing with the controls - or if you don't, I can't imagine how you could drive safely. Candidates that are more useful would be the type of information already displayed on the dashboard, especially anything you find yourself looking for regularly. (In my case that means the speedo on the road, and the rev counter on the track. And a big red 'CAUTION' light if there's any problem with the temps and pressures.) The rest of it? That's just a distraction.