Arguably the most stunning car at this week's Frankfurt Motor Show was the Porsche Mission E, a low, sleek all-electric sport sedan that is likely to go into production within three or four years.
It stole much of the limelight from the other all-electric debut, the Audi e-tron Quattro Concept, a lightly disguised version of what will become the Audi Q6 sporty crossover utility vehicle offered with a variety of powertrains.
But the Porsche was the more important, so it's worth looking at what it represents for the industry, for electric cars, and for electric-car startup Tesla Motors.
DON'T MISS: How Audi, BMW & Mercedes Plan To Compete With Tesla--And Why (Dec 2014)
Porsche was arguably the prestige carmaker most startled by the late 2012 arrival of the Tesla Model S.
That electric luxury sedan was lauded not only in the U.S.--by buyers and media alike--but also by the German automotive press, which suggested it offered a combination of qualities no German maker could duplicate.
For the three companies (BMW, Daimler, and VW Group's Audi) that are used to dominating the high end of the world's car market, that was deeply, profoundly unsettling.
Audi e-tron quattro concept, 2015 Frankfurt Auto ShowEnlarge Photo
And once they tested the Model S, and realized that it delivered on the promise of a good-looking, smooth, fast sedan that happened to run entirely on electricity, those three makers set about figuring out what to do about it.
The answers have varied from maker to maker.
BMW is by far the most advanced in electric-car technology, with billions of dollars invested in new technology ranging from carbon-fiber reinforced plastic (CFRP) body shells to a complete toolkit of electric-drive components.
But thus far BMW's two offerings are both in niche markets: the small battery-electric i3 city car, with 81 miles of range and oddball rear doors, and the sexy i8 gull-winged plug-in hybrid sport coupe, starting at $135,000.
With its clever optional range-extending engine, the i3 REx can achieve about 150 miles of range--albeit with some performance limitations.
But neither BMW competes directly against the Model S sedan or upcoming Model X crossover.
2015 Smart Fortwo Electric DriveEnlarge Photo
Daimler now offers the tiny Smart ForTwo Electric Drive and the low-volume Mercedes-Benz B-Class Electric Drive.
It is rumored to be developing a new line of electric-drive vehicles on a dedicated "EcoChic" platform, but those apparently will not arrive until 2018 or even later.
Thomas Weber, the Daimler board member in charge of car development, told reporters at the show that the company would introduce a different kind of battery-electric vehicle with 250 miles of range.
It would be, he said, "unique" and "emotional"--and it might arrive sometime in 2018.
Finally, there's VW Group, which is steadily spreading plug-in hybrid versions across its model range--from Golf compacts to Bentley SUVs.
Audi will have its Q6 e-tron electric crossover, more or less competing against the Tesla Model X, as well as several plug-in hybrids, including the 2016 Audi A3 Sportback e-tron.