Technically, the sales tax deduction lapsed after 2013. Congress for the last several years has waited until December to decide what the law is... and much of it is retroactive.
So, right now there is no sales tax deduction for vehicles and other major purchases.... but probably it will be un-lapsed (that a word?)... or renewed for 2014. Probably. So, if you are debating a major purchase and are looking for the best year to purchase, I'd say 2014 because it 'might' be a deduction. If we don't know about 2014 for certain, we have no clue what 2015 will be like.