Most states estimate the cost per mile of an automobile at above $0.50/mile for business expenses. When gasoline was >$4, that estimate was estimated to be $1/mile.

You're also not estimating the liability very well. Likelihood and cost of death or injury of 5 people MV to SF and back added with chances of uninsured drivers leaves most drivers well underinsured. Also, the statistical unlikelihood of having a fully occupied vehicle.

Other costs include road subsides, parking subsidies/real estate costs.