Even though Apple and Hyundai originally promised to bring their CarPlay infotainment system to the Sonata line of automobiles in 2015, that didn't quite happen. Whether the delay was because of licensing or technical issues, neither company has said. Regardless, they have made a new statement promising that CarPlay will be available for the Hyundai Sonata in the first quarter of 2016.
Hyundai indicated their plan is to sell an SD card with new software to get the system. They didn't reveal the price for the SD Card, but the installation itself shouldn't have any other costs associated. Here's a quote with a brief description of CarPlay's capabilities: