single piece as someone said earlier happened during the E plate. 87Es had the quarter light, the 88Es didn't.
they also changed the side mouldings, and a host of minor mechanical changes as well. the badges at the back moved around. the centre VW badge appeared on the rear, the VOLKSWAGEN name tag disappeared as well, and the GOLF became GOLF.
you could always spot a repaired Golf in the early days cause they also stopped producing the original rear panel. so if you were buying an older Golf with the centre badge you knew it had been hit.