Try adding a "Regional Market Price Adjustment" to your trade in.
"Oh, I know my car sells for $5k at auction, but I want $8k for it bc there's a $3k regional market adjustment. Oh, you don't pay those? Well guess what? Neither do I!"
(seriously, if you decide the BRZ is the car you want, you can buy one over the Internet from 5 States away and have it delivered to your front door for less than the cost of MSRP. No reason to ever pay over MSRP at this point.)