When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Be aware, the 2013 is not an all-new model, but only another model year of the 2IS. Prices are very good right now on new 2012's, and rates should get even better once the 2013's trickle in.
As far as which year is "best?" I love it when people ask this. 99% of the time, the newer the better. Age and miles kill a car, negating any advantages/disadvantages of feautures that were added or taken out over the life of a model.