I haven't played Sleeping Dogs in about a month, so I'm not sure if this particular hole has been patched yet or not. If you run and jump at oncoming double-decker streetcars in Central, you will pop right out the back of them, unharmed. I tried this about 30 times over the course of about 3 days, so it did not seem like a one-time event. Not sure how or if this could be used to anyone's advantage, but a little quirk in an otherwise excellent game.
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