Oil preheater in aluminum trans pan

A car might run consistent cold and hot weather because in the cold, the air is denser and produces more power, but the trans fluid is thicker; lowering the stall...so, ya, I'd heat that fluid somehow.
If I do this, the only way is an immersion heater. It is made by Stefs and is 200 watts. It measures 4 inches long and roughly 3/4 inch diameter. It is designed not to scorch the fluid. The element is enclosed.
Could you recommend where abouts on the pan I should locate the bung. I am looking at under the low reverse servo because I believe it would clear the filter when taking the pan off.