Toyobaru seem to be operating off regional allocations with each region determining who gets the cars, dealerships work with their regional person to get the car they want, not the car you want.
Ideally it would work the way you want it, order the car and you should have the exact car you want in about a month (that's the way mine worked out, but it was like pulling teeth). But no matter how friendly your neighborhood dealership is they're looking out for themselves first, they've got their next 3 months deliveries worked out the way they want and don't want to shuffle to get the car to your specs, maybe they're only getting one car a month and they've got three guys ahead of you. Doesn't matter, they're playing a game unless they only get 1 car every 3 months.
You could probably get the car you want over this way though, it feels awkward hawking this guy but he's really the only reliable way to get a BRZ with minimal hassle.
http://www.ft86club.com/forums/showthread.php?t=54679