i noticed that too, although i didn't make the insight link... i think with the increasing wider track of cars perhaps we're finally moveing back to those wheelfairings on 30's cars... who also had real boattails.... kind of like the aptera does in an extreme way
since it's real world Cd is about the same as the calibra i thought i'd overlay the profiles and lo and behold, an almost perfact match... because Cd-wise the new insignia is also somewhat in the same league i'd thought i'd trow it in the mix,and although it didn't match quite as nice, it's very close and in line drawing it actually looks surprisingly similar to the merc.... especially since unlike the other two it's stricly not a coupé but the regular 4 door sedan!
anyway, seems like generally this is a pretty good shape than!