a tranny cooler is a very good idea. every auto should come with one. odds are its not your tranny causing the hot floor, its your exhaust. its not leaking, its just that damn hot. the heat will radiate from the exhaust system onto the closest thing, your floor. now, you can X that by 100 if you still have your cat con. thats why there are heat shields around important parts. i have o carpet in my YJ, just bedlined floor. i could never drive in the summer with the doors on, its too hot. of course its too cold in winter too lol.