Car prices cannot fluctuate every time the dollar does. If the Cruze jumped by $5k and it was quoted as being related to the dollar, it wouldn't sell.
In fact, if the average transaction price increased because of the CAD:USD, overall new car sales would plummet and used sales would also suffer as folks would hold onto their cars longer.
It'll happen eventually, but don't think the manufacturers are being "nice" in not raising the price - it's calculated.