904 Transmission Leak

I'm getting my street/strip 71 Dart back on the road and ready to compete in Drag week this year for the 4th year in a row. I didn't think the car was leaking any fluids... first few test drives and the underneath was spotless.

The car sat in my car port for 4 days then I noticed a puddle underneath. With the car on jack stands I cleaned all the fluid up and off the pan. Took it for a drive.... got back and no leaks. Again the car sits for 3 or 4 days before it starts leaking again. Strange how it doesn't seem to leak while driving but after sitting for a few days. Anyone else experience this?

Dart 1.jpg