It depends on the reason you are trying to include vehicle expenses as part of your return. 

If you are simply claiming vehicle expenses for driving from home to work, then that is commuting expenses and is not deductible. 

If you have mileage to claim as an employee, then you would use Form 2106 to claim the vehicle expenses.  If you have mileage to claim as a self-employed person, then you would use Schedule C to claim the vehicle expenses. 

Search for ‘Form 2106’ or ‘Schedule C’ at the top of your screen to go to the section of your return that you need. Then TurboTax will walk you through entering the vehicle expenses for more than one vehicle.