I've been wondering if anyone with a manual transmission and a new radiator that comes with ATF nipples have ever used that portion of the radiator to cool some other fluids like for example oil or anything else. Normally I see them unused on MT vehicles. I just thought it was a waste not to use them for something.
Line diameter is way too low for oil. Take a look at any remote oil cooler or filter, the lines will be -10 or -12. Could possibly use for power steering fluid but then the high PSI could become a problem.
Not sure about the radiator, but if you run some spare ATF line or other hose through the rubber grommet in the floorboard and leave a couple feet in the cab, you can drink as many Big Gulp soda's as you want on a road trip and not have to worry about stopping. This, of course is generally for guys only. Your wife, most likely WILL have a problem with this arrangement.