Automatic costs are going to be license tags, gas, and maintenance of the car. At the time of the purchase and every year after, car owners have to pay a car tax to keep their cars registered. In general, a more expensive the car will have a higher tax. You do not want to be discouraging, but people need to consider these costs. Another cost that people forget about is parking for work.
Many companies have free parking.
But some companies that are located in downtown areas do not have parking lots, and the employees need to park in public areas that cost money. Encourage the students to check out whether they need to pay for parking. The students may need to do some investigative work to get the figures for these expenses, so a follow-up session may need to be scheduled. Write these figures on the board and divide the total by 36 months. This will provide a monthly payment for owning a car.