This has been my experience and your car at be totally different as they say. I used the
oil cooler opening with a cooler right inside the hole. Bad idea. The problem with that is the tranny cooler won't get enough air flow at slow speeds when it really needs it, unless it's ducted better than mine was.
Keezling brought up a good point about the road course. I've tried running on a course in auto. This track had a high speed curve that my tranny wanted to up shift on. That's not a place that you want to break the rear tires loose.