The key here is to start a reputation before you actually do anything. Start talking to your neighbors about the masked vigilante that has reportedly taken down a few would-be car thieves the last few weeks. Make these stories wild, but believable. Try and get these same stories fed to the shady apartment dwellers. Then a few times a week, go for a "19 minute 5K" jog through the neighborhood in your costume. Make sure you run through the apartment. Be seen...but not too seen.
Oh yeah, and get a skylamp that broadcasts your emblem. You do have an emblem, right?