I've had my '07 GT for a few days now, and it's time for the mods to begin. While I wait for the intake and tuner to arrive I decided to upgrade the mirror with a Gentex auto-dimming unit with compass, temp and Homelink. For a review of the process, complete with pics and complete description of the installation, see my web site here:
http://www.reverendbiker.com/mustang/mustangmirror.htm
http://www.reverendbiker.com/mustang/mustangmirror.htm