Some things off the top of my head. Of course I don't know what you have or what features you might want that you don't have.
Perhaps you want to grab the overhead console if you find one with more features than yours has. Though depending on what you find, I don't know what it would take to add the features.
Spare set of factory rims to put some snow tires on.
If you only have the AWD / 4HI / 4LO feature and not the 2wd selection that some models have, you could probably get the 4 position switch and wire it up along with the brown wire mod to make it more "factory".
I'm keeping all the window switches from the doors of the Expedition I am going to junk. The only local yard that has a good selection of Expeditions wants $40 minumum for anything electrical, even a single set of switches.
If you want the chrome (or not chrome mirrors)
GEM unit and fuse box can become toast if your windshield developes the famous leak.
The 2000 I bought had a couple weak door lock actuators, so I removed the perfectly good ones from the 98. I also plan to fully remove the remaining ones.
You might get lucky and find a keyfob in a glovebox or something.
Owners manual if you don't have one.
Maybe look for an alternator that was replaced for a high amp one, though most yards around me pull any alternators they think are good.
Push bar or tow hooks
Roof Rack cross bars to give you 4 in case you think you might neet that.
In my 98, one day I snagged the plastic trim piece between the carpet and the door on the floor and it popped out. Two of the plastic nubs that hold the clips broke (one broke and one got mis-shaped). It never quite layed right again, so I got a replacement at the yard. Unfortunately, I got the OTHER shade of gray.
You might find one with a FRONT mounted hitch receiver.
Front skid plate.
I guess you could check all the lights for LED bulbs if you were so inclined.
Maybe you'll find an HID conversion.
reach up under your front left wheel well and find the transmission dip stick tube. Feel it all the way down as far as you can. See if yours is developing a rust hole like mine did. Keep in mind, it's only like $35 from the dealer for the top half (it's two piece with an o-ring).
check under the driver seat towards the console for dropped change. Thats where I always find it in my vehicles.
Keep an eye out for a K&N sticker under the hood, which may tell you there is a K&N filter installed.
For that matter, look for any JEGS or SUPERCHIPS or other stickers that might tell you there is something aftermarket inside (I know SC wouldn't actually do any good to find).
