The problem is Canadians employ the metric system, but with US cars calibrated in imperial units, they cannot be allowed on Canadian roads and the cost of conversion is prohibitive.
Where are you getting this from? All you need to do is check riv.ca to see if your car is admissible for import. If it's over 15 year old it's automatically admissible, and under 15 years almost everything is admissible. Cars in the US are required to have metric on their speedometers anyway. If it's admissible and has DRLs, it's good to go, no changes needed.
The biggest problem with importing cars into Canada--1.) US dealers are prohibited by automakers from selling new cars to residents of Canada (and vice versa) and 2.) Canada import duty has to be paid.