If you have obtained Global Entry status and you are DRIVING into Canada, you will need your Global Entry card if you want to take advantage of the expedited immigration lines for Global Entry Travelers.
It is not clear if this includes travelers taking their cars onto the car ferries but it probably does, so be sure to have your Global Entry card with you.
Anyone traveling from the U.S. to Canada by air or vehicle must have a valid passport. The old days when you could drive to Canada with no more than your U.S. driver's license are long gone. Plus of course you need the passport to get back into the U.S.