Years ago when I had my Matrix XRS (miss that car) I approached a fella with another Matrix and tried to strike up a conversation about our cars...even told him about MatrixOwners.com. He looked at me like I had a pecker growing out of the top of my head. I haven't bothered since.
Now, it's happened the other way around to me though. I've owned a lot of cars over the years, almost all modded to some degree and people have struck up conversations about them. When I had my xB, other Scion owners waved, honked and talked to me at stoplights and gas stations. But I never initiated the conversations.
Gotta share this (concerning the xB)....best random quote from a non-Scion owner at a gas station, "That things electric ain't it? Bet it gets good gas mileage".