Those loops are “for vehicles without undercarriage attachment points.”
They are an accessory for a Thule (pronounced TOO-lee) roof rack.
Every car I’ve had has good sturdy places under the bumpers, front and rear, where the bow and stern of a canoe can be tied down. One problem can be the rope rubs against paintwork. In that case, use a piece of duct tape or plastic under duct tape to protect the paint.
I have travelled thousands of miles with a canoe or two on top of my cars. I have a Yakima rack on my Honda Civic. Thule racks are good, too. My Town and Country van’s factory rack and crossbars also work well.
The important thing is to make sure everything is secure and that any single failure will be detected and is not enough to let the load come off!