The MKIV website shows a drawing of an Euro spec supra with an aux tranny cooler installed under the drivers headlight. Not sure if this was standard on these cars or an option. The drawing showed the tranny fluid routed through both the aux cooler and the cooler in the radiator. It tied into the cooler line that is routed to the drivers side of the radiator. I'm not sure what order the fluid is flowing through the 2 coolers. I would think it best to flow through the aux cooler last.
The Euro cars came with some nice upgrades over the US version: functional hood scoops, glass headlights, tranny coolers, and I wouldn't be suprised to find out they came with drink holders!