[lunarhighway]

good question.

one thing to note is that car have an increasing wide track, this might be to improve handling,and since i have the impression most cars are a bit taller as well their center of gravity might be a bit higher as wel than the average car lets say 10 years ago.

styling wise these bold arches probably give the car a bit more muscular apperance... wich is a nice trick to give a small car or a potentially "boring" family car like the cangoo a bit more muscular appearance.

on the other hand i noticed you'r example of an "old" car is one of my favorites... and probably the one with the lowest drag of them all with and 0.28 Cd... so i'm not sure if these new arches are that much better than the old ones.

something else i've noticed is that on older cars there much more space between the wheen arch and the tire... probably because they had a little more suspention travle.