Latest on MP3 player add-in techniques

Hey everyone,

I want to surprise my wife by ripping the dash out of her '02 Nissan Xterra and adding a stereo phono jack so it supports her gadgetty MP3 player.

Yes, we're all sure she will be surprised alright.     However, to make sure I'm not surprised by a right-hook, I want to get it right.

I think the factory HU has an aux port, and there's no CD changer in the back. So I'm planning on using a PIE-OEM aux converter and a simple male-RCA to female-phono adapter cable. http://www.pie.net/store/index.cfm?Action=ViewCategory&Category=133

I am linking the cool chart they provide with specifics for almost every make/model so I think I found the right adapter. (my hope here is that others may also be helped by this, or else I'll get re-pointed in a more correct direction by you all.) http://www.pie.net/images/appguide/appl_aux-051206.pdf

Two questions before I open this shipment from PIE:

If I get the HU exposed and there's no AUX port on the backplane, does that mean the harness controls the AUX, and I need some kind of clip-in harness adapter? And if so, where's a wiring diagram for the existing factory HU harness? (I looked around a bit on the net, and only found pre-2000 wiring diags.)

What if the aux-oem doesn't work? My backup plan is a relatively-high-end FM modulator (not transmitter, don't roll your eye's too quickly.)  So, I'd like anyone's favorite/least noisy FM mod. described to me (by brand, please!)

Oh ya, and I wanna unveil this on Christmas, and it's pre-Thanksgiving now....so I encourage rapid replies!

Thanks very much for your support.