$277 pretax and no loyalty on a new Sport 1.5T at 36/12 Seems you are doing pretty well. I had ~279+ tax on the same car last month and at most there was maybe another $10 a month to be negotiated.
Get them to drop the mud flaps or as compensation add in a couple of service vouchers and you should be golden.
For comparison a Chicago broker was $263 + tax last month. Plus license and $180 doc fees. Not counting a $350 broker fee. So you have that one beat by $10-15 a month since no broker fee 
If you can get $294 all-in with tax you are doing well
And you can always buy it at the end for less than 16K