I live in PA and filled out some Yahoo Autos thing that sent my request to 5 Chevy dealers in the area. This was on Saturday morning and I got a few e-mail responses but only one called me directly and he called from his cell. I called him back, went down to this small chevy dealer (the name on the dealership owns dodge and ford in other towns though) and they had three 2013 sedans, all with 1.8L auto and one with MyLink.
I got to see the color I wanted though and had brought my iphone to test MyLink when I test drove. Took it on the hwy and got a feel for interior noise at hwy speeds, came back to dealer and placed order. MyLink is awesome, really glad I waited instead of pulling trigger on 2012.
Feel like I got fleeced on the trade-in but doesn't everyone? First time new car buyer, guess everyone gets to go through that. I understand their position and because I'm using supplier pricing I get from my credit union there wasn't much room for negotiating on the trade.
Anyway I'm pleased, I knew WAY more about the Sonic and capabilities than the guy at the dealership but he admitted as much. I pointed him to these forums and to some youtube videos showing how MyLink will do nav (he had no idea) and he seemed genuinely interested and down to earth.
Anyway, put money down for the car to place the order, accepted financing terms and will sign final financing papers when the car arrives in "8-10 weeks".
Super excited!
edit: Here is the link to the Yahoo Autos page for the Sonic. You should be able to pick your 2013 trim/options and have the request sent to your local dealers. Be warned though, it may not send the options you pick (or even the year of the car) so be prepared for a lot of generic responses.
http://autos.yahoo.com/chevrolet/sonic/