Why do you think they are calling it a Cadillac plan? Comparing it to transportation is pretty much the point.
So, where does the Tata Nano fit into your analogy? Not everyone can afford a car with anti-lock brakes, airbags, an engine capable of propelling it to highway speeds, that's capable of meeting EPA requirements for air pollution, etc. Why can't we have the $2k Nano? Or the $5k Mexican produced Beetle?
I'm not a fan of Obamacare, but let's keep the debate on the reality. You can still get your Chevy Sonic of the insurance world, and you can still get your Cadillac, we arn't forcing everyone in to the upper end of the market. There's plenty of real issues with it, the constitutionality of forcing everyone to buy, the fact the penalties are much cheaper than the insurance for young and healthy people who are needed in the mix to subsidize the older and sicker, etc. The "Cadillac plan" is false and removes the focus from the real issues.
Well, as I said, all analogies have failing points. You sorta lost me with references to particular car models, but I don't agree with your premise -- we CAN'T still get a Chevy Sonic (whatever that is -- assuming it's a cheap, bare-bones car.) THAT is the entire point of the analogy. A Chevy Sonic or a Yugo, for that matter, is bare-bones. It doesn't have electric windows (neo-natal care), a cigarette lighter (drug dependence treatment), heated seats (low-cost drug supplement), etc. Unless you're just an ideologue who completely buys into the premise that the ACA is Constitutional, necessary and well-designed, I don't understand your confusion. The Bronze Plan (as I understand it) has a lot of the stuff that people neither want nor need -- and certainly don't want to pay for.
I don't mind that you don't like my analogy, but your argument is not solid. If I don't want all the extras in the cheapest ACA-approved insurance plan, I have no choice. I can't buy basic transportation that fits my wants and needs -- I have to buy THEIR "basic" car ... which just happens to have electric windows, a cigarette lighter and heated seats.