I use stick-on convex mirrors on the driver's outside mirror. I also adjust that mirror depending on whether I'm doing city or highway driving. For highway driving, I set the mirror to see more behind me than beside me. Maybe partly because highway driving often involves the cargo area piled high with stuff. If you're going to see very far behind you, you are going to see the rear flank of your vehicle.
My formative driving years were in a truck, so I never became dependent on the inside mirror.
Which raises a point others mentioned. The article assumes the inside mirror is fully functional. With cars having 5 headrests, and high back ends, not to mention the proportions and loading of suv's, bicycle racks etc, the inside mirror is often severely compromised, and the positioning described in the article may itself be outdated.
The article also falls short in that it does not address added convex mirrors and the fact the passenger side mirror is universally convex these days. Is the writer unaware of these things?
Almost regardless of the circumstances, I check the right outside mirror when turning right to make sure there are no cyclists there.