No, you'll need to trim the bezel, just slightly to get it to fit. Since the bezel is wider at the top, it requires less trimming up there, but I see how putting the nav. system up top would be best. Jim has pictures of two headunits (empeg + aftermarket) in a WRX at riocar.org somewhere. Here we go:
[image]http://riocar.org/albums/album73/aae.sized.jpg [/image]

More Images.

Technically, the Accessport would void your warranty, but since it can't be detected, it doesn't matter. I have done a ton of stuff to my car and my dealership still honors my warranty as long as what breaks isn't due to what I did. Altough, the only thing that happened to my car was a "known issue/almost recall" type thing. Been very reliable other than that.

Not sure on fuel economy. But since you also get 30+ more horsepower, you may actually get LESS mileage because you drive it harder.