You can turn down the visibility (brightness) so it is not visible. Why would you want to do that? You have several options of the type of information that is displayed in it as well as being able to adjust to some degree the height of the display on the windshield.
OP, can you edit your title of the thread to something more meaningful like "Heads up display can you turn off" or "Can the HUD be turned off?"
its nice when the thread has more meaning such as subject lines in emails. I am a systems network administrator/engineer and I just cringe receiving emails with either no subject line or the word "help" it is more productive for me if the user can have some sort of description in the subject line such as "Help server is down cannot access files" versus "Help" or "Help my email does not work" now which email do you think I will open up first and address? and the worst emails are the ones with no subject line, I take my time on opening those up and addressing
I don't want to come across as someone being anal but take a look at a really good thread titled
"Anyone annoyed by the red and blue lights (OnStar) in the rear view mirror? " that's what I call descriptive