I analysed all tracks:  wings for marie pt 1 is a different bpm to wings for marie part 2.  This therefor makes it impossible to mix the tracks together without inconsistencies.  Unless you were to alter the bpm as they do when they play electronic music in a club, perhaps they could go together - but that would also alter the time of the song and then it wont be exactly the same length as pt1. So, there ya go - I dont think this was something they set out to create, its just a fluke.