Many car DVD players with very thin glass touch screens have multiple non-reflective plastic layers under the thin glass. Mine on my Hummer has four such plastic layers, each layer is designed to reflect glare from one of four different angles (left/right; top/bottom). In bright sunlight with the DVD Off, sometimes you can see the streaks caused by the anti-reflective plastic layers; depending on the angle you are viewing the screen on the DVD player. If you disassemble this type of screen you will see that each plastic layer resembles a see-through window blind (best way I can describe it). So if looking at the screen from a left and/or right angle, you will see vertical lines; if looking at the screen from the top or bottom you will see horizontal lines. They are not solid lines, and my guess they are a type multiple polarizer filters preventing glare on the actual LCD screen under the touch screen. (There is also another layer under the anti-glare layers for touch screen operation.) Possibly, and I say 'possibly,' this could be what people are seeing? I do believe the screen is somewhat anti-reflective; more so than my D70 was or even my D200.
By all means I do not intend to break my D300 screen like I did my Pioneer AVIC screen just to see what is under the glass.