How would you crop this?

[dejv]

I've taken this picture some time ago and I quite like the scene it captures - streetcar passing policemen with ice cream and beer stalls in background. But I can't find a crop I'd like either because the tram gets too close to new frame border or I've got people going out of the frame or I'm getting to square-like aspect ratio. Can somebody of you see a different crop that I don't see?