I still think the best bet for reliable data is going to be from old Car and Driver mags.
They give a Cd and frontal area for most all cars they feature. I am sure that at least one member here has to have Car and Drivers dating back to the mid 90's.
I think that the 94-98 would be the most aerodynamic. it has a more round front end and transition to hood. the fox's have a steep angled front end which would deflect a lot of air around it's edges instead of over. I wanna draw a picture. It's gonna take a while.
pics are uploading (dialup) so anyways the reason why I think that the 94-98 is more aerodynamic is because of the smooth, streamline-ish, rounded edges the nose has. I figures all you know about the bernoulli principle, but I'll state what I remember anyways.
some guy named bernoulli realised that fluids and gasses tend to follow curves, this is why water will drip down a ball, or spoon instead of dripping OFF of it at it's farthest out point. with aerodynamics, the faster the air travels over a curved surface the more likely it will want to fly off of the apex (dunno if that's the right terminology, but I mean it to be hte highest point on a curve.) now if the apex is not a curve but a sharp edge, it will be much more difficult to go around, or over, the air tends to fly off and stitch, creating turbulence and a low pressure area. this is a bad aerodynamic signiture. gosh it's late.
green is hte direction of the plack anlge (sharp edge would be fox, smooth would be SN) I can't draw for ****
blue is air, red is low pressure, or drag.