Production of Tesla's first car aimed at a broad market, the Model 3, is under way. CEO Elon Musk said on Twitter Saturday that the first production Model 3 was "built and going through final checkout."

Musk then shared photos of the first car on Twitter and Instagram.

He said last week that production of the Model 3, Tesla's least-expensive all-electric sedan, would start ahead of schedule, because the car had cleared regulatory hurdles two weeks early. Production growth would be “exponential,” ramping up from 100 cars in August to roughly 5,000 sedans a week by the end of the year, he added.

The car starts at about $35,000, while Tesla's flagship Model S starts at $69,500.

The first 30 buyers are scheduled to get their Model 3 cars at an event on July 28.

Tesla said in April that there are 115,000 U.S. orders for the Model 3, and that anyone ordering one now should expect delivery near the end of 2018.

The automaker has a lot riding on the Model 3. One of Musk's original visions for Tesla was to ultimately create an affordable, high-volume car. But Tesla at times has struggled with higher production. For instance, the company said last week that "the major factor affecting Tesla's Q2 deliveries was a severe production shortfall of 100 kWh battery packs, which are made using new technologies on new production lines."

Consumer Reports will anonymously purchase a Model 3 to put it through testing at our track.

Photo: Elon Musk