Long Doors, now standard, came in when airbags had to be fitted in some markets. This meant the dash had to move further away from the seat. As a result the de-mister vents were no longer possible.
As a result there were changes to the structure of the front of the cockpit that allowed longer doors to make entry and exit easier.
It is all explained here:
4/4 And here:
100 years Buy them, essential reading!!
