Hi Snoops:
I checked this on my car when it was delivered and they cover the whole windscreen hitting it just around the middle line.
These jets are very similiar to those in my Honda. I had to have them changed under warranty thrice. They are, to the best of my knowledge and if anything like the Honda's, non adjustable.
I might be wrong.
PS: If they get blocked, then you tend to get a trickle hitting the bottom of the winscreen.