Sydney,
There are 2 phases to this process, I know all to well as they caught me earlier this year

There is the export and the import process. They caught me on the export process, I had no idea I had to stop into the american border as well if exporting from the US, but you do.
I am from New Brunswick, lived in New Hampshire a couple of years back, bought a 1989 pickup 4x4 xcab through cars.com, drove it in the US for a year, then moved back home to NB. Stopped into canada customs, did the &$^%#&*@ conehead vehicle import registry horse compost and thought all was well. The vehicle import registry makes sure the safety and emmisions on the vehicle complied to canadian standards the year it was manufactured. if anything didn't, you will be responsible to get the vehicle in compliance. Daytime running lights is the biggest violation there. They can also get you for not having french air bag warning stickers. So it varies. If you know what year and model you want, it would be helpfull to contact the morons at the vehicle import registry to see if that particular vehicle model complied with canada.
Anyways, I move back to New Hampshire this spring. Cross into the US and the border dude wants to know if I imported the vehicle to the US yet. I told him I didn't figure I would have to since I bought it there. So he asked me if I had my export documents. I did not. They charged me $1000 fine for breaking US customs law. APPARENTLY you are supposed to contact US customs a week before you export a vehicle from the country. They take some info, and check the title on the vehicle, make sure it isn't stolen etc. I assume. So when you show up at the border you have to stop in to US customs, and they should have had enough time to clear you by then. You get your export documents and you are on your way. Costs next to nothing, pays to be informed though
I was totally pissed, I drove it back and forth for a year before I took it out of the country and never imagined I'd have to stop in to see customs in the country I am leaving. This happens for nothing else that I am aware.
With that said. It is hugely worth it in my experience. Unlike in the maratimes, I live in a rich area here, all of southern NH has a lot more money then back home. Used vehicles are wrth nothing. I could wait a year before I'd see a toyota truck appear in the fredericton Daily Gleaner. There are always 5-15 within a 200 mile radius of Gilsum, NH here. Great prices and lots of trucks. Go further south for no rust. They NAIL the roads with salt around here.
keep an eye on cars.com, you can specify a region and keep an eye on it for a while.
thats my 2 cents,
Pete
http://members.localnet.com/~mkcooper