i have personally bought and exported from the U.S.,imported into Canada serveral times with no hassles. like workinonit says the title and bill of sale are absolutely key, without exception. we flew into san Diego last year and drove a 1963 suburban all the way up the Californian coast hwy 101,through Oregon then Washington. all you need to do is take a photo copy of the title to any autoplan insurance broker and ask for an insurance "binder" that way you are insured for the sole purpose of transporting the vehicle by driving it yourself through the states and into Canada. the binder is good in Canada until the date expires, hopefully it'll pass the provinical mechanical inspection before it expires. if it expires you can get a manually issued one day permit from any autoplan broker/agent. it's very simple. the border is a breeze, at the Candian side alll they do is hold their hand out to collect the 6% gst as it will be duty exept if old enough. they base the gst on what you paid in American that is first converted into Canadian funds.
cheers