Maybe they are referring to one of the New Yorkers? But killing Reed off will be hard for Mac as he is the only living connection between him and Claire (Conrad Taylor). And obviously we can't kill Lindsay...but what if she does get in and shoots the windows or something then gets out...maybe she'll be sick for a while or something. I am just coming up with assumptions
if you watch the preview again look closely (or pause it. ) on the part where the hand is opening the door. I may be seeing things after watching it so many times but it looks like the hand is attached to a man wearing a white dress shirt and a black dinner jacket because you can see the cuffs on his sleeve when he goes to open the door. So I think they just want us to think Lindsay gets in to the killer's cab when she really just gets in a normal safe cab. well as safe as cabs can be anyways.