A Body WAGONS-Ho! A body Wagon Thread

I don't have a Wagon but I have a Wagon related question that I have always wondered... Why did the 63-66 wagons get the more open, round rear wheel arches but everything else here in North America (4dr, 2dr, convertible and even the Barracuda) did not?

To make them the sexiest 63-66 models built :-)
I'm thinking about trying to change the wheelwells on my GT hardtop to wagon wheelwells, too

(Probably the real reason is that they didn't want to make different quarter panels for the Valiant and Dart wagons, so they picked one shape and stuck with it, but that's just a guess)