Please help identify this part

Hello everyone,
So my coolant has been leaking slowly and I finally spotted it today when it just leaked alot after I stopped the car.
It is coming from this part that is behind the engine air filter. (see picture)
What is this part? and do I just have bad hoses or something else? It seems it only leaks after I shut the car off and when it did leak alot of coolant dripped out ( a cups worth )

The part is marked with the letter A. It was leaking off of this so not sure if there is something else around the area that would leak and have it drip off of this.

Here are the symptoms i've had.
2 weeks ago low coolant light came on and I topped off.
It was fine but I noticed that the coolant needed to be filled up every couple days.
1 week ago same syptom as above a cups worth of coolant dripped out.
Car would shake slightly when I come to a full stop, stops when it is in park and when driven only when stopped.
Today coolant light came on while driving to work. Went to lunch and came back and after the car was stopped above sympton where almost a cups worth of coolant just dripped out fast and I noticed it is from this part.

Thank You

realoem.com

what year is your car? I"m guessing 2007+? It looks nothing like what I see on an M54 engine...