Why do people think that mandating car insurance is the same as mandating health insurance?

I could choose not to drive. Also even the democratic legal think tank advisers have said there is no legal precedent for mandating the purchase of health insurance from a private company. If they don't have single payer or even a public option it may not hold up in the supreme court.
--------------------
Because liberals are about as deep as a puddle. They're different too because for some reason health insurance covers everything! Why can't we pay $40 for a doctor visit? Insurance should be for catastrophic situations, like hospitalization. Could you imagine how expensive car insurance would be if we decided to roll in costs for changing wipers and oil changes? That's effectively what we've done to health insurance.
Source