One main reason is for the quality, fit and finish the Kia vehicles have over most American brands now. This has improved yearly with many awards and accolades for the Kia brand.
Second is the rich feature packed content applied to the Kia vehicles over its competitors. Some standard features on Kia models cost with other brands and Kia is also known for having features other brands don't.
And third a 10 year warranty on new vehicles that Kia has been doing for years.
There you have it just 3 great reasons but I could go on. As the brand preps for 2016 models we move ahead to the near future. Enjoy.