I noticed that at the bottom of the transmission there is a bit of ATF accumulating.
It is right where the gearbox and engine join.

There are no oil stains under the car. It idles for about 5-7mins in the garage before I take off and still no oil stains.

The leakage is very minimal, and it seems that it is only while running.
What could this be? And is it an expensive fix?

Also, the ATF is red in color. Is this the correct color of genuine Mercedes ATF?

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Smoke Silver 1994 E220 Coupe Automatic
0 kilometers 6 September 1994
100,635 kilometers - 6 September 2010