I have an 02 X50, purchased new (yes, I paid the full $17,000). Nav in O2 was not standard. I purchased it as a factory option, and Porsche subsequently refunded my total option cost, when I described the abysmal performance of that system. If it is already there in the car you purchase, fine, if it isn't, you wont miss it. It only works well in large cities.
The X50 value is not apparent until you call Kevin and get the re-flash. I also took his advice on the Europipe (after a huge mistake on the Fabspeed). Then the car totally comes to life and you recognize all the potential the factory kept concealed in the X50 option. I have multiple 500+hp cars (CTS-V coupe, MB CLK Black series, and a couple of vintage racers with aluminum V-8's) and the 996ttX50 can keep up with all of them. AS

 

Nav makes dash looks nicer and not necessarily for it's navigation use...

 

attached is the nav unit on an 04. I replaced the cd holder with a cubby hole, but that is the layout.

 

Actually, only on manual tranny there is no 0-62mph improvement for X50 option, but on tiptronic it's 4.8s (420hp) vs 4.5s (450hp) for X50. I have an X50 car.

 

What is the button immediately above the cigarette lighter? Looks different to mine?

 

Footwell Lights. The cigarette lighter and delayed wiper control are also reversed from where they are on my car (GT3). Maybe US vs RoW car for your question?

Cheers