eh is certainly a Canuckism but more common in Central/East than out here. I have wondered if it arose from the Quebecois hein, "Tu vas en ville, hein?" (there is an accent but I can't find it on this computer and with my techno-klutz tendencies it would take all night to find it)
It is always irritating to read a Canadian character's dialogue written by someone from another country as the eh's are in the wrong places. The trick is to put it where you would use the US huh, "New hummer, huh?"