always downshift BEFore the turn.

 

Bingo

 

True, that was a bad example.

All of this makes me think of a new example. Does an automatic transmission ever shift in a corner?

 

no, autos usually downshift upon really hard deceleration to assist in breaking, but not all of them do this. most downshifting is done when you hit the go-pedal. If you are mid turn and floor it in an auto car it MAY downshift if its not dependent on the yaw sensors.