I noticed in the manual for my '06 Sonata that the transmission is only
supposed to be fed some sort of proprietary SP III fluid. I was at the
dealer today for a headlight issue. While wandering around, I noticed that
they had boxes - kind of like those wine boxes - of transmission fluid. The
box said "BG Universal Synthetic ATF" part number 3123. I asked, and was
told that that fluid is what is used by them in the new Hyundai
transmissions. That said, I guess the requirement for the $8.00 a quart
specially blessed fluid is non-existent. After all, what would be so
different about one brand of synthetic fluid, and another?