Paying the highest rate loan first will always save you the most money, unless you have a tax break.
You should figure out what your deduction is for your student loan interest. There is a max $2500 deduction, but it phases out between $55,000 and $70,000 ($115,000-$145,000 if you are married and filing jointly).
Also, this is a deduction, not a credit, which means it only reduces your taxable income, it doesn't come off the top of your tax bill. So to figure out the "benefit" of the student loan interest, you need to figure out your tax liability with it and without it. (For example, if you got the full $2500 deduction and all of that money was taxed at the marginal 25% tax rate, your taxes would be reduced by $625. If that money was taxed at the marginal rate of 15%, you'd only be reducing your taxes by $375.)
With that big of an interest rate difference, it is unlikely that paying down the car loan first will be the option that saves you the most money.
While the "snowball" approach is emotionally satisfying, it only makes financial sense if you would otherwise not pay down your debts. (Snowballing is better than not making progress on your debts, but if you will make $X of extra payments on your debts regardless of whether or not you get the emotional satisfaction of seeing one paid down, then paying the highest rate first will save you the most money in the end.)