Anti freeze seeping from back of 1995 A6 V6 engine
 

Hello everyone this is the first time I have posted so please forgive me if I am posting in the wrong section.
Over the past couple of days I have been seeing a puddle of anti freeze on my garage floor. Not very much, but anything is not right. The leak is coming from the rear of the engine just below the black box which sits at the rear. Could anyone give me some more information what heater hoses etc might be at the rear of the V6 engine. By the way its an automatic wagon. I am sure its not a head gasket as this was I believe very rare with this engine.
Any advice would be welcome, thank you. By the way I love the car has over 130,000 miles on it and has been running wonderfully all these years.