Go to the web sites for BlueOx, Roadmaster, and Demco. Find the base plate (towing brackets for Roadmaster) that fits that model car, download the installation instructions.
Those instructions will show how each tow bar manufacturer does an installation, each may do it differently. Demco and BlueOx may be most similar, because they permanently install a base plate to which the tow bar attaches.
Roadmaster may use different attachment points, because they install permanent brackets to which an external cross bar (serving function of base plate) is temporarily attached. I've seen a number of Roadmaster installations that don't go through the fascia at all, they go under everything to some point on a front subframe. There is more design flexibility, the way Roadmaster does it.
Tom Test
Itasca Spirit 29B