I don't know about Canada but the US import laws are very stringent. Basically it can only be imported if the vehicle was sold in the US for the same year of production. For example, you could import a 1990 BMW 5 series but you would need to convert it to 1990 US specifications. You cannot do the work yourself either. The work must be completed by a government certified conversion shop. I've heard that the conversion work (change out glass for DOT glass etc) can easiliy run past $7000. I'm not sure if this applies to vehicles from Canada but this is the rule for vehicles coming from Europe.
For something like the Jimny, you could never import into the US until it was basically 25 years or older. Then all the DOT requirments can be waivered. That's how I got my Beetle in. Since it was nearly 50 years old at the time, it went right through customs despite the fact that it is euro-spec (no turn signals etc)
There are some shady ways of getting vehicles in (VIN swaps) for LWB Samurais and that works because most people don't recognize the difference between the SWB and LWB versions. However, if you have something that was never sold in the US and does not meet US DOT/EPA standards...well you can pretty much forget it until it is 25 year old.