My car shipped with 2015-1. (April 2015). I was able to download, put the 2015-2 on a usb stick and update. No codes needed
YMMV
As to differences, not really.. since I did it soon after getting the car it's tough to say. I don't remember so much detailed junction guidance? just a feeling may be wrong.
YMMV
As to differences, not really.. since I did it soon after getting the car it's tough to say. I don't remember so much detailed junction guidance? just a feeling may be wrong.