Deductions & credits

The company I contract with reimburses mileage at the IRS rate to contractors but does not report it as income. I should still be able to write off the property tax on my vehicle (based on percent business miles). The only way i can figure to enter this in turbo tax is to enter my business miles as business miles....then go tot he forms and manually switch it to deduct actual expense and enter only my property tax as an expense. this prevents turbo tax form deducting the mileage which was already reimbursed. Is this the best way to do it?