The BMW 3 Series coupe and cabriolet was firstly introduced at the end of the year 1999 to 2000. The present model has the vehicle body code E46. It uses the same hood structure and the front body as the previous model. The most difference from the previous model is the front headlight and front bumper which can be divided into 3 models, sedan and station wagon models, coupe and cabriolet models and the compact models.
From the information above, you can see that the minor change for the BMW 3 Series is mostly independent from the fact that there are many models for it. They dont need to minor change all 3 groups at the same time. The first minor change is for the sedan and station wagon since the end of the year 2001 and come along with the minor change for coupe and cabriolet in the end of 2002 but the actual release date was around March in 2003.
The minor change for coupe and cabriolet models can be easily seen by the front head lights. It includes all high, low beam and turn signal in the same frame and changes the color of the turn signal from yellow to transparent white. The turn signal on the side of the cars moved upward and change to blurry white instead...