After a sluggish start in its Model S car production, it seems electric-car company Tesla is getting back on track for the year's end. Reaching a milestone today, Tesla CEO Elon Musk tweeted that his company had just finished the production of its 1,000th Model S car.

As noted in Musk's tweet, Tesla has made more cars in October than the whole rest of the year combined. In a July letter to shareholders, Tesla said its Model S volume projection was 5,000 units for 2012. However, Tesla's ability to crank out the Model S has come into question.

Several analysts have worried that the company will make fewer cars than earlier estimated. Originally, Tesla thought it would make 1,000 units per month and end up with 5,000 units in 2012 and four times that many in 2013. Tesla also said that it expected to deliver approximately 500 vehicles to customers during the third quarter, with the balance shipped out during the fourth quarter.

The car company began deliveries of its all-electric Tesla Model S in June. With its release, the Model S came out as the most practical electric car yet. Given its range and luxury sedan packaging, it was seen as becoming a daily driver for its owners. It also came with the added benefit of costing about a tenth less to run than a gasoline-engine car.

It's not yet clear if Tesla will get up to its 5,000 units by the end of the year. With two months to go, that would be 2,000 vehicles per month, which is possible but would mean the car company would have to increase production even more than it did in October.