My 2008 F150 Rcab did not have a sliding rear window when I bought it. I found this aftermarket unit:

CRL Tri-Vent Three Panel "Perfect Fit" Slider with Light Gray Tint Glass 2004+ Ford F-150

Here's a link:

http://products.crlaurence.com/Produ...2.html?Origin=

They also have power models, but I personally really don't need that in a regular cab.

Thanks in advance for any information,

Hank Murphy
2008 F150 XL