must buy in multiples of two

All Castrol ATF qualifies, including the CVT fluid. Note that this price makes it cheaper than Amazon, and it's even cheaper than Advance Auto Parts' Castrol ATF sale (AAP's sale price is 2/$11)

I just picked up four bottles of the Castrol Full Synthetic ATF.

And now, some sad news about Autozone: they raised the price of the Maxlife gallon jug. It is now $25.99 (it used to be $19.99)