Water leak Mercedes AMG GT C V8

Hello dear friends, I just wanted to ask if someone here has the same problem as me. My AMG GTC V8 (built in 2018) greeted me one morning (after a very rainy day) with condensation on the passenger window. No problem I thought it was clean and I didn’t think anything about it. Until I noticed that the carpet was wet. From the workshop, which it could not explain itself, however, they checked everything and it was “repaired”, the workshop said that the rain would come from the rear. Everything was ok until the next rain came and so again the same problem. It went back to the workshop (that was three months ago) and the workshop has built the whole car apart, checked everything, cleaned and assembled again. I got the call to pick up the car, but it rained the night from the call and there was a call from the workshop again: The condensation was there again. But now the workshop, and I too is finished with my Latin. Does anyone from you have this problem too? Thank you very much for your answer in the LG, Anna.