Rear window deflector?

I saw a nice yellow '04 today that had a matching yellow, solid, single piece wind deflector mounted on the rear door over the window. Is this a dealer option or aftermarket?
Thanks.

Have seen them as aftermarket on ebay; color matched.

Thanks Bios!
I found them (they're known as "spoilers").
The Ebay seller has poor feedback so I googled and there are some reputable suppliers on line.
I think I might get one because a)my back window is a dirt magnet and b)they look really nice.
Thanks again

Does anyone have pics of these? I would like to see how they attatch

From most of the ones I have seen you have to drill into the rear hatch to attach it.

Check these out:
http://www.oepros.com/store/catalog/index.php?cPath=43&sort=2a&page=2

The Nissan one is like that - but worth it since it really does keep dirt and water off the back glass....

At one point someone posted a picture from a club outing where two Xterra's were parked side by side - same color, one had the deflector and the other didn't - the difference in accumulated dirt was astonishing...

The pic is from www.xterra101.com

That's not the one I'm thinking of, but it serves the purpose.

Still hard to believe every time I see it.

Hmm, they are back at Xterraparts.com . They want $95, my dealer want's $75 - how silly is that? Think I'm going to order it tomorrow. All the rain lately has been a pain...