When you return to the U-bahn line 6, go one station back, towards Siebenhirten. Exit at station Michelbeuern - Allgemeines Krankenhaus. Leave the station and do not cross the street towards the hospital, but go to the other side of the street. There you will find the Antonigasse where Kara's apartment is located. The Antonigasse is a long road and it takes about 30 minutes to walk to the apartment, since it is located all the way at the other end. But it's worth the walk.
You might remember the old Eastern European look the street once had, with its cobble stones. These have mostly disappeared and can only be found on the parking spaces on both sides of the modernised street. You will also remember the tram line driving past Kara's apartment, and you will probably wonder, like I did, why there is no visible tram line track on the Antonigasse. Are we on the wrong road then?
Truth is, as you will notice, the tram line actually runs through Kreuzgasse, the street running parallel to the Antonigasse. But all the way at the end, the tram line leaves the Kreuzgasse and runs for just one block through the Antonigasse, to return to the Kreuzgasse immediately afterwards. Here's where you will find Kara's apartment.