There are now 100,000 Tesla Model S electric cars on the roads, and its Model X crossover finally struggled into production last fall.
Since that time, long-range plans by Tesla Motors for a third, smaller, and much less expensive range of electric cars continue draw huge interest.
Little bits and pieces of news have filtered out, but now the big allure is the promised public debut of a concept for the car this spring.
Here's what we know so far.
EDITOR'S NOTE: When we first published this article in June 2013, Tesla had built barely 10,000 Model S cars. A great deal has changed for that model in two and a half years, but we've learned remarkably little about the Model 3 since then. Still, with its debut just weeks away, we thought this was a good time to update the piece as much as possible.
CODE NAME: The new compact sedan was originally called the "Blue Star," following in line with "White Star," which turned into the Model S.
Tesla Motors, Palo Alto, California
MODEL NAME: Tesla had intended to call its third-generation car the Model E, meaning that its three volume vehicles would be the S-E-X trio. We'll leave you to ponder that one.
However, Ford turned out to have a prior trademark on the Model E, and declined to release it. The car that Tesla intends to be its high-volume, mass-market entry is now called the Model 3.
Typographically, that is often rendered as three stacked horizontal lines, as in the Tesla logo. We don't use that on this site because the character doesn't render properly on all devices.
BODY STYLES: A compact sedan, described as a BMW 3-Series competitor, will come first.
It will be followed by a crossover utility vehicle on the same platform, which Musk referred to in a 2015 tweet as the "Model Y"--following on the Model X larger crossover, presumably.
2016 Tesla Model X with 2011 Tesla Roadster Sport, photographed by owner Bonnie Norman
POSITIONING: Musk told Bloomberg in May 2013 that the new model will be a "compelling, affordable car" that's far less costly than the Model S, but nicer than the high-volume Nissan Leaf.
"What the world really needs is a great, affordable electric car," Musk said in the interview.
"I’m not going to let anything go, no matter what people offer, until I complete that mission.”
ALSO SEE: It's Official: General Motors Now Sees Tesla As A Threat (Jul 2013)
RANGE: The new model will have a range of about 200 miles, Musk has often said.
There may well be more than one battery offering, as there is in the Model S, to give higher ranges at additional cost.
TIMING: When the Model X was expected to go on sale at the end of 2014, Musk said the new, smaller Tesla will go into production in late 2016.
That timing has now moved to the end of 2017 or early 2018, and if history is any guide, that date could slip further.
Tesla future plan timeline shown at 2013 annual shareholder meeting
Volume production in the hundreds of thousands likely won't occur until 2020 or so--assuming everything goes well.
We now know, however, that Tesla plans to unveil a design for the Model 3 next month.
Rumors suggest it will be at the Geneva Motor Show, but that would be atypical for Tesla, which rarely appears at or makes major announcements at auto shows.
We also don't know if this will be a design study, an "alpha" development vehicle, or a proposed final production model.
2012 Tesla Model S beta vehicle, Fremont, CA, October 2011
COST: The new model has always planned to cost roughly half of what a Model S does, with Musk acknowledging that the large luxury sedan is "too expensive for most people."
The consistent quoted price has been $35,000, which Musk clarified was before any incentives are applied.
The CEO suggested a few years ago that by the time the Model 3 goes into volume production, Tesla might have used all of the 200,000 Federal income-tax credits allowed for each automaker.
With production now running at roughly 50,000 cars per year (50,557 in 2015), and a total of 100,000 Teslas on global roads, that's a distinct possibility by 2018.
2012 Tesla Model S beta vehicle, Fremont, CA, October 2011
STYLING: Musk said the Generation III car will have "a family resemblance" to the Model S. (The first-generation Tesla was the Roadster; the second-generation cars are the Model S and Model X.)
Beyond that, absolutely nothing is known about the car--and thus far, no spy shots have even emerged.
BATTERY TECHNOLOGY: Tesla has said nothing about its battery technology for the new vehicle, nor has it specified pack sizes or options.
But we know that volume production of the Model 3 will require high-volume cell fabrication and battery-pack assembly at Tesla's first gigafactory outside Reno, Nevada.
The electric-car maker and its cell partner and part owner Panasonic continues to work on more energy-dense cells and cost reductions for high-volume cell fabrication.
Musk said three years ago that he was "pretty optimistic" that the necessary advances in battery technology are achievable without "any miracles happening."
Tesla gigafactory: Planned 2020 production of lithium-ion cells [slide: Tesla Motors, Feb 2014]
OTHER TECHNOLOGY: Musk hinted that the new line might have some elements of autonomous driving, but suggested those might not be offered right at the launch.
Last fall, the company launched what it calls a "beta" version of its Autopilot self-driving software for Model S cars equipped with the necessary sensors, those built after August 2014.
The Autopilot system uses both real-time data from onboard sensors and a database of experience from other Teslas previously traveling over the same route to allow the car to drive itself under certain conditions.
SUPERCHARGER NETWORK: One of the most important features of electric-car usage has turned out to be widely available DC quick-charging, which provides up to an 80-percent battery recharge in 20 to 40 minutes.
Tesla's fast-expanding Supercharger network is far ahead of the two other competing standards for lower-priced, lower-range cars, and the company shows no sign of letting up on the pace of installation globally.
Tesla Motors Supercharger network in the U.S. - map as of January 2016
Musk has said in the past that the Model 3 will be able to use the Supercharger network, just like any other Tesla (except the Roadster).
It remains unclear if Supercharger hardware will come standard on all Model 3s, as it now is on the Model S, or whether it would be an extra-cost option.
You can rest assured that between now and the launch of the next line of Tesla cars and crossovers, there will be more coverage of every detail.
Lots more coverage.