I just read on the 360 board, find a girl that kisses you (green diamond at street level on your map when the alarm is raised), kiss her, lower alarm, shoot gun a block a way, raise alarm, kiss girl, repeat.
---------- Favorite Game ever = Morrowind; Band=tool; Song=Bat out of hell: movie= Apoclypse now; Party Favor=XTC (MDMA).
If anyone's still looking for a good spot, I just uploaded my method on YouTube. I doubt there's a faster way to get the trophy as long as you haven't blown up the watchtower that I use to raise the alarm.
Alright just did it now. The church where you find Denis, on the steps where the 3 jumps are, going from the top jump down once and they'll be a woman you can kiss standing between benches and next to a sign with headshots on them. What you want to do is walk around in on the street the level above where she is and find a guard. There's usually only one walking around. Go near him, shoot and let him blow his whistle than kill him. Now you can either kill the 3 Nazis that will come in a sturmwagon or sprint to the girl which usually works because when you jump down to where she is, the Nazis will lose sight of you. Repeat this 50 times.