I think they should go to alternating current for cars, and skip the DC part.
While it's true the battery has be charged at 12 VDC, and the starter requires 12 VDC, it seems like they should just keep the alternator output as AC, and step up or down the voltage as appropriate. AC motors are more reliable and simple.
Smoking indoors does a lot of damage to property, by leaving a thick film of soot on the walls and ceilings of buildings. The public shouldn't have to pay for cleaning on public housing due to smokers. Smoking is a disgusting habit due to all the pollution it produces indoors and out, and with all the cigerette butts.
If people want to smoke, they can smoke outdoors, just like they have to do in most other public buildings in most states. You can't light up in a library, an office building, grocery store, or most government buildings anymore.