Originally Posted by
njkayaker
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You can see people fairly-well (not perfectly). If the cars aren't obscuring each other, keep in mind that the rear window isn't (generally) tinted.
I'm guessing from your usename you're from the east coast. Out here on the west coast, dark tinted rear windows are a regular feature. I look for waves of thank you from drivers I have been courteous to. About one in three I cannot even see through the rear window because it is so dark. I've also had the drivers who looked right at me, seemingly seeing me, and still opening the door at that perfect time. In general, I don't look very hard for people in parked cars. Sometimes they cannot be seen, sometimes they do the ridiculous so having seen them gave you no useful information and that whole time you were looking, there was other stuff you weren't looking at or seeing.
Ben