Production of its new electric SUV "has been increasing exponentially," the company said Sunday, adding that it's on track to start making 238 Model X SUVs per week. 

The company also unveiled how many of its customers got their cars in 2015, and it wasn't as many as the company would have liked. 

Deliveries were at the low end of the guidance CEO Elon Musk gave in October of "between 50,000 and 55,000." 

And that estimate was weaker than Musk's initial estimate in March that the company would reach 55,000. 

But it has high hopes for 2016. Tesla's new "Gigafactory" in Nevada is fired up, and the company is now selling and churning out more vehicles than ever.