there is a few diferences, to name a few, the front light configeration (obviously) were moved to the wings (to comply with some law apparently) the 2a was the first to have the 2.25L diesel put in also the first series to have the 2.6L in a straight 6 format in the 109 as a option. but many early 2a are in no real way (few things like window wiper motor ect were changed) different to the series 2. im shure there were a few other things as well but somone else will be along to help (probly correct me aswell :) )
