Just to clarify how this is supposed to work:
A stock system send the transmission fluid through the radiator to cool. The problem with this is that the transmission fluid temp will "follow" your car's coolant temp.
An "in-series" system places a mini radiator AFTER the radiator to provide additional cooling of the transmission fluid after it has already been cooled by the engine radiator. This provides a mild improvement and a good option for most of us. Also, for those of us in cold climates, the warmth of the engine coolant will help warm the transmission fluid in the winter - a good thing.
A "standalone" removes the stock radiator from the system and the transmission cooling depends solely on an additional, appropriately sized, radiator for the transmission only. This provides the most efficient cooling but I'm not familiar with how to size correctly.
If you placed your transmission cooler before your engine radiator the transmission fluid will be cooled before the engine radiator and then warmed up again once it goes through the engine radiator. You likely will see zero improvement.
