My son is a mechanic & he said to use the DEXRON-III Automatic Transmission Fluid. From what I understand, the fluids are essentially the same but the ATF may have some harsher detergents in it. It could actually make the leak worse.

I'd probably schlep some LUCAS in it for a while to see if that helps with the leak. I've run it before without any problems (not in the VX though).