You need to enter it as a Business Vehicle Expense under Business Expenses, go through all the interview questions, and opt to NOT take the mileage deduction, but to take the "Actual" expense.
After that you will be asked how you want to take the depreciation, and if the vehicle is eligible, you can take the 179 deduction.
Be aware that the vehicle must be used MORE THAN 50% for business to be eligible for the deduction.
