Harper gets driven around in a 300C, while the Governor-General usually has a Lincoln Town Car with special plates. They might have also used Buick Park Avenues on occasion.

There was an interesting article I read the other day about American presidents and their personal cars; unsurprisingly, most drove brands such as Chrysler and Ford although there are some exceptions. For instance, Lyndon B. Johnson owned an Amphicar that he liked to drive into the lake at his ranch while George W. Bush once owned a Triumph convertible.