Hello  
From what I've heard about New York is that it's a big place right? Like, if you were living in a small town of a small number of people, I wouldn't put toooo much importance of running into her but I think the fact it's New York makes it extra strange and 'coincidental'? I live in a relatively small city of under a million people and I usually stay in and around the same specific areas but I still have barely ever just 'ran into' exs or their family even. I think it happened once that I ran into an ex on the street. So I think you're attracting these people to you because of your vibration. However, the reason that you are not seeing him could be for a couple of possibilities: You seem to worry over what he 'might' be thinking, like want he wants you to know and not know. You say that he wouldn't want you to know what his car looks like? Really? Why do you think that? Do you harbour some belief that you think he thinks you're a stalker or something? Do you feel as if you're a stalker or something? Because I wouldn't care if my ex knew what my car looked like if they happened to see it. Big deal, who cares...unless I thought they were a stalker ! So stop thinking in any way like that because it's all negative....
Another reason is because you're looking at the fact you're running into everyone but him and feeling down about when you shouldn't bother because that's keeping him from you too. Let go of that attachment, start just focusing on other things when you feel your mind going that way. 
The final reason you might not be seeing him is because the manifestation is too built up in your head so you're holding it apart by wanting it too much. Letting go or 'letting be' is all about just deciding that your life is worth living and you can choose to be happy and if you're not getting what you want from somewhere, just go do other things for a while and look at other places and emotionally in many ways move on so that you can shut down the attachment and desperation. That will lead you to seeing him and more, but only if you're genuine. I feel that you're still a little bit too stuck on the obsession phase and the wanting phase. I haven't seen my original person around just out of the blue, I've seen him at certain events I knew he'd be at, but I haven't seen him just around. It doesn't mean much though, because I've had boyfriends contact me after ages and not seeing them around. Not seeing someone around doesn't mean that you never will see them again or that they won't contact you. Get off the manifestation of just 'seeing' him because it's too obsessive and pointless too.