There absolutlely are worthwhile CDN cars, but I bet they pretty much all tend to be the newer ones. Unless you find a nugget from someone who has owned the car since new, could be tough to find an older car that checks out great.
FYI - when I was looking, I looked at 5 or so over the span of a few months. 4 of them were excellent vehicles and one of them may have been good, but there was enough ambuigity, and enough alternatives, to rule it out.
I chose the one that made the most financial sense of the 4, and it just happened to be the best color too!
Again, all newer cars with about or less than 10k km on them.
I bet that if you find a really good older car, that its price will be out of line if you consider newer cars also. That would definately make life difficult.
If I were looking for an older car, Id focus almost exclusively upon cars of known and responsible PRIME users.