I agree. I put small convex mirrors on the lower part of my big mirrors, which makes it handy for seeing what's in the blind spot. I still turn my head and look. This gives those in that lane the idea that I might be moving over.
It's all about eye contact: at intersections, lane changes, parking lots, garages, entrance ramps.
Luke M
Used to have a 1979 CB750L, sold it as a parts bike, now riding a slightly modified 1984 VT700C. Network/Field Engineer. Central OH, USA, Earth, Sol System, Milky Way Galaxy, Universe.