Ford was the volume leader with sales rising 7.1 per cent.
Air conditioner bolt can fail and pulleys can fall onto road.
The bank has revised its 2013 forecast for Canada to 1.735 million from 1.72 million units.
Ford led the way with a gain of more than 10%, selling 22,635 vehicles for the month, up from 20,561 a year ago.
Analysts suggest if sales continue at their current pace, 2013 will be a record year for auto sales, topping 1.7 million units.
Without more investment, it will run out of gas.
Ford, Chrysler see increases of 7% while GM inches up 0.1%.
The head of General Motors Canada says he expects auto sales in Canada to be flat or slightly down in 2012.