Pretty much the same reasons as everyone else.
HID's
Navigation
Blacked out headlights
LED DRL's
And because it's a Subaru
The lights and Subaru name are what attracted me the most. I always bought aftermarket HID kits, and having it stock makes it that much easier. The front end of the FR-S with the lights on make it look like your average car, with the yellowish halogen bulbs and orange DRL's. But the LED DRL's and boomerang make this car really stand out. Nothing against Scion owners, but I tend to prefer the Subaru crowd myself.