We have been searched once out of probably 20 crossings (one 5th wheel and two different motorhomes). 99% of the time its just a few questions...mostly about weapons, alcohol, bringing anything you plan to leave in Canada (gifts), how long you plan to stay, why you are entering Canada, where you are going. Some times we give a window of time...we are retired, somewhere between 4 to 6 weeks. Sometimes questions about food items. We generally don't take much fresh stuff either direction so that is not an issue.
We make sure we have registration and proof of insurance but have not been asked to see it. If your name on the passport matches the information they get from the license number on your vehicle then that should not be an issue. We also make sure any medications are in the original container.
As stated earlier...just be honest and respectful.