You're not including an amortized cost of maintenance, registration fees, etc. Adding in tires alone ($720 for a set, 50k/1200 ~=41 months, ~$17.50/mo) brings it to almost $290/mo. Oil change every 6 months or so, add another $10/mo or so. Now we're at $300/mo and hoping nothing in the car breaks and needs repairs on a car that's already paid off, and we still haven't paid our taxes and registration fees.

Now figure in the fact you've got several thousand dollars in a car instead of even something like a high-yield savings account. At even 4% APY, if you had just $8k tied up in that car that's another ~$27/mo of income you're missing out on.

I'm not making the argument riding a taxi for every trip is cheaper than this. Just pointing out there's a lot of things people don't think about when they think of the cost of car ownership.