The all-electric Tesla Model S sedan is brilliant, beautiful, as user-friendly as a smartphone, fast as hell, quieter than C-Span, American made and years ahead of its luxury-sedan competition. But it isn’t perfect. I see things I would change. Those jazzy polished-zinc door handles, for example, part of the cabin’s circumnavigating bands of alloy and leather, weren’t shaped for human hands. The 17-inch capacitive touch screen panel that dominates the forward cabin still seems clumsily placed—design by procurement. I expect Tesla’s next-generation touch screen and graphical user interfaces to be fused across the forward...