vss aka speed sensor

I'm looking at this head unit http://www.crutchfield.com/App/Prod...wAll=N&g=168550&i=105KDNX500&tp=75&tab=review its overpriced at cruthfield, but I can find it on other sites for under $700 shipped...

anyways... after reading the reviews, I noticed lots of people are having trouble locating their vehicles vss/speed sensor (its needed for the navi) Can anybody tell me where it is on a 2001 LT hoe before I order it?

The VSS will keep track of the vehicle's location when the unit loses the satellite(s) signal through tunnels, parking garages, tall surrounding buildings, etc. It is fairly easy to locate and tap into; you can go either to a two pin plug on the tranny or at the PCM in the red connector, pin 20, grn/blk wire.