Except that the Volt is a Chevy Cruze, their current Chevette, albeit with an electric motor in addition to a gasoline engine. The Hyundai Sonata is not their starter model, rather it is right in the middle of their model line, their Taurus or Camry, as it were.
Well, I’m not in the market for a car right now so I haven’t compared the Volt to the Cruze side by side in fit and finish quality. I suspect that there are significant differences, structurally and with the interior. The weight distribution, climate control, sound deadening, dash controls etc. are necessarily going to dictate big differences. A Cadillac Escalade and a Chevy Suburban probably share more common components than the Volt and Cruze, but have very different levels of comfort, fit, finish, quietness, etc. I don’t know that the Volt being “based on” the Cruze automatically means it will feel as lowbrow as a Chevette.
A vehicle LIKE the Volt, with a 25 - 50 mile all-electric around town range independent of fuel but unlimited range with fuel makes a lot of sense to me. 90% of my days I’d be able to avoid using any gasoline at all. Unfortunately, CA has ridiculous electric rates, so I wouldn’t see the kind of savings that I would if I lived in NV or somewhere with $0.10/kwh rates. At $40K, it would never save enough money for anyone to justify it on that basis. Barring significant differences in quality and comfort, I think the Volt at $25K would be my choice over the Sonata.