Funny you should ask, I drive an 04 WJ Limited w/ options very similar to the Overland trim. I don't have the UC package, Nav or adjustable pedals, other than that I'm pretty much optioned like a Overland. I have about 145,xxx miles on the clock and just had the CEL come on. I must preface this by stating that the Jeep has been reliable over the 5 years I've owned it. Only non maintenance items that have gone bad are the alternator and this CEL, which sounds like a speed input/output sensor. Things to watch out for though are bad/failing rubber seals (look at the door pieces) and if the interior lights turn off with the car or that the windows/sunroof work. There is a common failure in the drivers wiring harness where the ground cable will snap, causing the light/window error. I took mine to a car audio place to run a new wire and voila, problem solved (albeit, after I attempted a fix with butt connectors & a soldering gun).
You can easily check for fault codes by turning the key to the AC position (where dash lights come on) and then off 3 times within 5 seconds. Leave it in the AC position after the third attempt and you will see a Pxxxx number on the odometer. That is your fault code. If none show up, then no CEL! Please note, this is the first CEL I've experienced with this Jeep. I don't want to scare you away, but the Jeep is almost 10 years old, so things are going to start falling apart on you.
Before I forget, there is another common failure on Jeeps of this era where the blend doors on the dual zone climate control fails. All this means is that you don't get dual zone anymore, whatever the driver temp reading is, is what you'll get on the passenger side as well. I have not had this problem yet w/ mine though. Head over to WJJeeps.com for tons of reading. There is a very active forum called JeepForum (as well as others) where you can find anything out you want.
PSS wanna buy mine?