At one time the bumpers were deemed not to be up to the Canadian standard, this was BS and now they accept the US standard as being OK, I think it had to do with converting kph to mph, 8 and 5 spring to mind.
Some people paid big bucks to convert to DTRL's, I read somewhere that this was done at Canadian Tire for $30 or so. Others had to buy new switches and they cost $$$$$$
If you knew this already, I am sorry to waste your time but in case you did not ...
There are more threads on importing cars you just have to search.