I thought all trans fluids were synthetic already? I know MANUAL transmissions has both regular and synthetic fluids (GL-5) , but as far as I know there's only one kind of auto fluid.
I have (to Mobil1 synthetic), and I think someone on here posted pics using the same product. Don't know how much better the product is, but upon draining the old fluid at 26,000 miles, the previous fluid was completely black.