[inferiorhuman]

Sure, but I said "if you're going to have a car anyway". And I, and I think most people who can afford it, am going to have a car even if I use mass transportation daily. If you ride the bus, you're not paying any less in registration, insurance, or car payment until you actually sell your car.

Sure and if you're riding the bus, train, cable car, etc. instead of driving the $500/mo you're paying becomes less worthwhile.

But let's say you're driving from Mountain View to SF daily, that's about 40 miles. Let's say you consistently get 30 mpg (unlikely if there's traffic or if you're driving something large) and let's say that gas stays at $3.50/gal. That's almost $190 in fuel alone. Parking, if you want a reserved spot, is about $300/mo in San Francisco. Daily rates are closer to $400/mo (or at least that's what I've had to pay for parking along the Embarcadero). So you're looking at $500-$600 in addition to whatever it costs to own the car. That's nearly double what you'd pay for Caltrain (which is typically not a bus).

Obviously things get more expensive if you buy something more status symbol like that requires high octane fuel or gets worse mileage. Things get less expensive with an electric vehicle but parking is still extremely expensive in San Francisco.