I have an '04 model with over 16K miles. No window failure nor lock problems. No electrical problem.
Since i don't tow, the ParkTronic is a big plus for me. It makes parking the G a piece of cake. Without it, it would be a pain the butt because of the small rear window.
The Harman Kardon stereo is pretty good...good clarity and solid bass...the only minor negative is that imaging is not always perfect (due to shape of interior). NAVI is also improved because you can route from one region to the next on one CD-ROM.
The seats are multicontour, as stated above. It's pretty much useless, EXCEPT for the lumbar support. I cannot stand a seat without lumbar support...and i am not even that old
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The new headliner is classier, IMO...but, i am bias. Steering wheel controls are better integrated.
And i would get extended warranty.