The Status Bar is something we all use often in Civil 3D, but probably take for granted. Other than the change from using text to icons a few years back you might not think about it much as you use it day to day to change settings and toggle features like object snaps on and off. However, since AutoCAD Map 3D is part of Civil 3D you do have some features available on the Status Bar that you my not be aware of.
This is the standard Status Bar in Civil 3D.
If you type MAPSTATUSBAR at the command line and select the option to Show it you then get a Status Bar with more features.
Now you will see the expanded Map Stats Bar displayed. It has several additional features, most notably it shows the coordinate system that is assigned to the drawing. The graphic above is from a drawing with no coordinate system assigned, so it displays <none>, all you have to do is click on that button to assign one or change it.
This expanded status bar also has options to display Features from the Map 3D Display Manager in 3D and change their vertical exaggeration.
So give it a try and take advantage of having the drawing coordinate system displayed on the status bar. You will enjoy never opening a dialog box just to check it again.