I’m using TurboTax and having a large purchase other than the house for the first time unsure if or how to use the sales tax deduction. So I go through and get the Energy-Efficient Vehicle deduction, yay! Then I get to the sales tax section and it says don’t bother as TurboTax thinks the income deduction will be better for me. But knowing I had paid the cars sizable sales tax I went ahead and put in the CA sales tax info and the federal refund amount went up. TurboTax then says the sales tax deduction will give me the maximum refund. TurboTax says that you must chose to use the sales tax or income tax deduction but I paid more in income tax than sales, is it double dipping?