bringing car into Canada

I am moving back to Canada in about three weeks after spending two years on a H1 visa in the US and I have a few questions with regards to bringing back my cars.

I have one car that was purchased in Canada and brought over in 2008. It is licensed in NC but I never went throught the paperwork of"formally" importing it into the US. I checked with RIV and they told me that this car does not have to get into the RIV process of importing a car into Canada because it was purchased in Canada. I am suspicious of this answer and was wondering if anyone has had a similar experience.

The second car was bought in the US and so I have to go through the import process which is described on the RIV website. First step is to get paperwork stamped by US border after 72 hours notice. By calling US border, I found out that they do not accept faxes (unlike what is stated on RIV website), so I need to bring the original paperwork myself (or mail it). The problem is that I will not cross during business hours, so I will have to bring the car back to the border at another time. Beside this hassle, does anybody have any advice to offer?

Help is very much appreciated.