the original VW Motoring Magazine from the 16v doesn't actually say.
however, in the beginning of 88 (mid E) the car moved onto the bigger front window surrounds, and the VW badge went to the middle on the rear panel. The slanted/italic Golf logo also appeared.
as far as i can tell most of the golfs had a couple of enhanced component changes, but nothing like the mechanical make over the 16v got.
essentially - everything changed. alot of components that changed also became ghost parts with the 357 code, which is the G60/Rallye code. this includes much of the steering, suspension and braking systems.
if you try and swap parts between a D/E and a late E 16v you will run into a lot of problems.
i thought the bigger brakes came with this change and not the late 89 make over, which only added big bumpers and PAS. However, in 89, they also started to remove bits and pieces, like eletric windows and sunroofs i think (dont quote me on this).
i don't think the late spec had better or different running gear from the late E model. the change in the running gear, if we are talking about things like bearings, changed in 1988.
the first reviews of the 16v were Feb 1987. So we are talking D at the earliest.
Tin