When they started putting in padded dash tops in the late 60s they'd overhang a couple inches. If you weren't careful your knuckles would hit the dash pad going into 2nd and sometimes prevent it from going into gear. Not sure how it was with GM cars, but was a PITA on Mopars.
I taught my sisters how to drive manual on my mother's Saab with 4 in the tree. Had to be careful not to bump the wiper lever when you'd shift, especially for those of us with large hands.
Anyone remember the free wheeling on those cars? Hard to describe to someone who's never driven with it, but if it was engaged it would essentially put the car in neutral and let it coast if you let off on the gas. I suppose it saved a little gas, but you had no engine braking.