My local dealer likes to use Hershey's Chocolate Syrup in the transmission. It works really good, and its tasty too and doesn't smell as bad when it burns. That's obviously false, but I have been using Castrol Multi Import SPIII for the last two years and about 27k miles with no issue. I did notice some tiny seepage, but not enough to cause a drip on the ground.
The transmission shifts far superior with the Castrol Multi Import SPIII vs the stock Hyundai fluid.
