For over a year I attempted to provide Hyundai with the necessary documents to be refunded for the engine replacement my 2011 Sonata required. In the end, they just dropped my case and said I didn't have enough information. However, I had all of the information they could ever want.
My conclusion is two fold: 1. Hyundai makes terrible motors. 2. Even if they say they'll stand behind their product, they didn't for me.
After you watch my story, check out other stories as well and it doesn't take long to realize that Hyundai motors are poorly made and have a terrible track record. Just type in 'Hyundai Engine issues' and you'll see what I mean. They're attractive cars, and they seem to be gaining popularity, but look behind the curtain and they are NOT a quality product. That's just my opinion.