As of this morning, I have just under 207,000 miles on my '06 Sonata 2.4L. It's my daily driver (125 miles round trip each day) and I expect to be driving it for a long time yet. Other than body work after hitting a deer - and two months later more body work after having another deer run into the side of me - I haven't had to do any significant mechanical repairs to the car. I haven't had to do anything other than routine maintenance to either the engine or drivetrain. In fact, besides the deer repairs the only non-routine maintenance I can recall is having to replace a switch for the manual shifting mode, which stopped working. The switch wasn't in the transmission, but near the bottom of the shifter itself. Simple repair, but it cost a couple hundred bucks to have done. This car has definitely given me much bang for the buck. I'm still getting 30mpg city/hwy combined, and 31-32 highway depending on how much lead is in my foot. I use synthetic oil and Napa Gold filters. I change the oil every 5,000 miles.
BTW, mine just became a 4-Hyundai family. My oldest son has (my old) 2001 Elantra with nearly 180,000 miles on it, my youngest son has a 2004 Elantra with around 65,000 miles on it, I have my Sonata, and my wife is the proud owner of a 2011 Santa Fe Limited we bought less than a month ago. For me Hyundais are incredibly reliable and economical. As long as they stay that way I will be buying Hyundais for a long time.