Traditionally, they were two completely different cars but I get it. They’re a lot more similar in size and style now. I still see the 6 as a large performance luxury 2-door. Always had a thing for large 2-doors. The mid 90’s MB S-Coupe is another one I admired. I still put the 6 and 8 in two different categories but I get what you’re saying.
Sure, that’s plausible. Maybe the flip headlights vs the shark nose that made me perceive them differently. Also, what their MB market competitor would be and not merely by size comparison: 7 Series-S Class, 3 Series-C Class, 5 Series-E Class, 6 Series- SCoupe/CL Class, 8 Series- SL Class, etc….