This problem happened two years ago when the car was only two years old and only had 17000 miles on it. I bought the car brand new. I was driving, all of a sudden the car kind of jerked, made a klunking sound. The car immediately slowed down almost to a crawl without me touching the brake pedal. I hit the gas trying to make the car move and it wasn't really helping. I was close enough to my house to get the car home (very slowly) and immediately called roadside assistance. They towed the car to Hyundai. I was told by the dealer that it was a solenoid valve inside the transmission. The part was covered by my warranty. Downside to all of this is that they kept my car for 3 days and I had no other car to get me around. When I picked the car up they told me everything was fine. Well it wasn't. One week to the day later same thing happened. I was driving, car jerked, made a noise. Again I had the car towed to the dealer. This time they tell me that the transmission needs a bunch of parts replaced so they are basically rebuilding the tranny. I asked why they wouldn't just put a new one in and they said the warranty company wouldn't approve it. The warranty did cover the rebuilt transmission so at least I didn't have to pay. The problem this time is that they had the car for 5 days. So in a matter of 2 weeks they had the car for 8 days total. I was pissed. I've been told this isn't a typical complaint for this car but I wanted to put it out there that it happened to me