Here's my auxiliary cooler:
I picked up a Heavy Duty cooler off the shelf at my local Advance Auto Parts. It is made by Hayden but branded as an Imperial.
I removed the stock transmission cooler connections and had this connector: (photo was taken by Sir Sam's post)
The hose included with the cooler slips right over the barb nicely. Be sure to use the included hose clamp to clamp it on.
Unscrew this sensor
And slide the cooler in
I cut a small notch here to make room for the hose:
Top View
It was an easy job, took around 30 minutes. This cooler fits like a glove. I used some stainless steel tie straps and L brackets to secure the cooler.