When it was unveiled at the 2009 Detroit Auto Show, the Cadillac Converj concept was widely lauded for its looks.

That was likely the last time the car that became the Cadillac ELR range-extended electric luxury coupe won any praise.

After an on-again, off-again, on-again history and a launch at the breathtaking price of $75,000, the ELR languished in the market from Day One.

DON'T MISS: 2016 Cadillac ELR: More Performance, More Range, Lower Price

It's been on sale for two years now, but only a couple of thousand have found buyers--and while updated 2016 models are now available at a few Cadillac dealers, discounts on the 2014 ELR reached tens of thousands of dollars.

Not surprisingly, Cadillac's marketing chief Uwe Ellinghaus told Automobile magazine that the ELR has been "a big disppointment."

In an interview largely centered around a discussion of how the Cadillac brand is perceived, Ellinghaus suggests that Cadillac still needs plug-in vehicles--both to meet tightening efficiency and emissions standards, and to underscore a more progressive image.

2016 Cadillac ELR

2016 Cadillac ELR

But he admits of the ELR, "Maybe we asked too much. We tried to create a car that was the niche in the niche in the niche and that was where the volume ended."

It was, he lists, effectively a two-seat coupe, with the very highest equipment specification, and in the plug-in niche to boot.

And, he acknowledges, it got compared to the Tesla Model S, whose $75,000 base price today equals the price at which the ELR launched.

MORE: 2014 Cadillac ELR: $75K Electric Coupe Gets Five-Figure Discounts, Already

While the Cadillac had every feature and the Model S at that price did not, one was a two-door coupe and one was a four-door sedan that could accommodate five people.

Going forward, Ellinghaus says, "we’ll simply add plug-in hybrid-electric modes into almost all our cars"--an approach that mirrors that of Audi, BMW, and Mercedes-Benz.

And, he believes, those buyers who want solely battery-electric power--no engine at all--will be "a minority," while the majority "particularly not in urban areas, will need longer ranges, and for them, a plug-in hybrid" will be the best solution.

2016 Cadillac ELR

2016 Cadillac ELR

Ultimately, Ellinghaus says, hydrogen fuel-cell vehicles are the way forward.

He states (incorrectly) that, "If you look at the environmental balance of electromobility as it is now, it makes no sense whatsoever"--presumably referring to wells-to-wheels carbon footprint, which is lower for plug-in cars today for most U.S. drivers than even a 50-mpg Toyota Prius.

Sometime after the gasoline version of the new Cadillac CT6 large luxury sedan is introduced in the U.S., a plug-in hybrid model is likely to be added.

ALSO SEE: Cadillac CT6 Plug-In Hybrid: Big Battery, More Electric Range

That version uses an adaptation of the 2016 Chevrolet Volt's second-generation Voltec powertrain, with a battery pack of the same size--18.4 kilowatt-hours--and a likely electric range of 20 to 30 miles.

Meanwhile, the Cadillac ELR remains on sale using the first-generation Volt powertrain. Most analysts expect it to fade out of the Cadillac lineup sooner or later.

If you like the looks of the ELR, you can probably get a great deal on one these days.

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