It's that joyous time of the year when we figure out our tax obligations. As you travel down the bumpy road of deductions, you may be able to write off a few car expenses, including some tied to insurance. Auto insurance premiums and business use of your car: Are you self-employed and use your vehicle on the job? Or are you employed but use the car for work-related reasons at least part of the time, without being reimbursed for expenses by your boss? If so, then you may be able to deduct some of your insurance premiums, says Leonard C. Wright, a San Diego-based financial planner and spokesperson for the American Institute of Certified Public Accountants. First, you have to determine how much your vehicle is used for work, says Wright. For example, if your car is used 75 percent of the time for business and the rest of the time for personal driving, then you can typically base your deductions on that split of percentages. In this case, you would deduct 75 percent of your auto expenses, including insurance premiums, gas, oil, repairs, registration fees, lease payments, depreciation, parking and toll fees. You'd list the expenses as miscellaneous itemized deductions. But keep in mind that you can only qualify for these deductions if they total more than 2 percent of your adjusted gross income. In other words, if 2 percent of your gross income is, say, $1,000, your expenses would have to be above that to claim all the write-offs. The alternative is taking the standard business mileage deduction. The Internal Revenue Service has set it at 55.5 cents a mile for 2012, with all expenses (including insurance premiums) figured in that rate. There are restrictions, however, and Wright advises studying the IRS guidelines or talking to a tax consultant before going this route.