When I accidentally overfilled my trans, the end result was the pan gasket seal blew, and a LOT of fluid was dripping underneath the trans.

No smoke though, so I would have to wonder if perhaps in your case, the excess was coming out of the fill tube? After all, it is in the proximity of the exhaust manifold...

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2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car