Kia Motors America has sold 557,599 units in 2012, an increase of 14.9%, compared to the same period in 2011.
The company claims that the sales of the US-built Optima was the best-selling vehicle every month and sold 100,000 vehicles in 2012.
Together with the Sorento, Kia's US-built vehicles accounted for 48.7% of sales, and the Soul urban passenger vehicle totalled 100,000 units.
KMA and KMMG president and CEO Byung Mo Ahn said, "As Kia continues to grow and strengthen the brand, we remain committed to advancing value to new levels of sophistication by introducing vehicles with world-class design, technology and amenities."
In November 2012, Kia Motors revealed plans to invest $1.6b over the next 16 years in West Point auto assembly plant, Georgia, US.
Kia Motors Manufacturing Georgia completed a series of expansion projects totaling $100m to increase annual capacity to 360,000 vehicles.
