I have Routis, but I haven't tried it in the car yet (I tested it on my home PC). Alot of people here raved about it, so I looked into it and noticed that it supports Canada and the US in one package. So I bought it. Once I finish fabricating the carputer, I'll be able to give a better answer.
Two things I like about Routis,
1) It talks (turn left, turn right, etc)
2) It supports 3D map viewing.
You can find Routis at http://www.deluoelectronics.com . I bought it bundled with their Deluo GPS.