I have been correcting geological maps using Bing imagery in AutoCAD. The imagery is good enough to see the features. I want to transpose to ArcMap to access good topographic information. I'm having trouble resolving at hundred mile scale. Unfortunately, a lot of work was drawn in AutoCAD with an unusual coordinate system (AZ83-WF) that has no ArcMap counterpart. Still, it seems the Bing coordinates should be absolute and splines drawn over it should also be absolute.
I agree that AZ state plane western foot should correspond to AZ83-WF. I have tried that with no luck.The problem seems to be that auto-cad projects the base map, in my case bing maps, and leaves the drawing as is. ArcGis also refuses to reproject autocad objects, and further insists that base maps remain in WGS84. I played with arcgis for autocad today. It has a promising feature called assign and list coordinate system. Unfortunately, it simply ignores my AZ state plane requests.
Ultimately, this seems to be a case of bad luck. I arrived at the AZ state plane trying to resolve a Geological Society of America map (without success). It was just left there when I discovered bing. All you can draw on is WGS84.