If you have excessive wear on the inside of the rear tires from lots of highway miles you can adjust for that with a more neutral alignment. These cars come with significant negative camber to maximize grip in the corners because it is a sports car, not a Camry. If your typical driving style doesn't include a lot of "sporty" driving and you are seeing excessive wear to the inside shoulder you can adjust for that with a more neutral alignment taking out some of the negative camber.
If it were my car and I mostly commuted on the highway I would go to a specialty alignment shop and request an alignment to maximize tire life. It would look something like this:
Front: 0 camber, 0 toe
Rear: -.5 camber, 1/16 total toe-in
This will result in the gas best mileage, longest tire life at the expense of max "sporty" grip in the corners. All alignment settings are a tradeoff so choose the one that best suits your driving style. Often that will differ from what your dealer may suggest.
For my car I want just the opposite. The only time it is on the highway is heading out to "sporty" roads and race tracks. I want max cornering grip at the expense of everything else. My alignment looks more like this:
F: -2.6 camber, 0 toe
R: -2.0 camber, 1/16 toe in
It is a good match for my driving style and my tire wear is pretty even. I run soft compound tires so they don't last very long (3-5k mi) but they do wear fairly evenly across the tread.
Set your car up for YOUR driving style, not your dealer's driving style.
