I keep my hardware faders way down because the physical volume control on my monitors is in the back. It's a pain in the neck to set, so I leave them at 12 o'clock. 
 
If I leave my audio interface hardware fader (in Sonar) at unity while working, the volume would be painful. 
 
When I am ready to export audio, I have to make sure to raise the hardware fader to unity or the overall output of the exported file will be affected. 
 
Sometimes I forget to do that and my exported files are so low in volume that I have to redo the whole process.
 
Worse, sometimes I forget to LOWER the fader back down to start working again and I blow my ears out as soon as I hit play. 
 
Any thoughts?

Huh?
 
How can Sonar ever be aware of the position of your hardware fader?
 
If your Export is low in volume then there's something wrong with your export procedure, nowt to do with hardware outside of Sonar.

I would look into controlling your listening volume at your interface, which may also have software control.
 
Short of that would it not make more sense to adjust your physical monitor settings so the maximum level is indeed the maximum level you would ever want to listen at?

The volume of the exported files are only dependent on the "volume, pan & gain" what you see at the left of the track.
If you have motorfaders setting this controls you need to set them to "0".
Therefor I have an analog mixer to control the speaker volume so that the controls in Sonar are not affected.
 

If I understand you are setting the level at the mains in your project. If you want you can override these at bounce time by choosing source category buses and then pick just the Master bus (the one that all other buses send to which is the final output stage in the mix)

I can fully appreciate the OP.  I think what is being asked is, "Can export be done 'pre master fader'?"  I would love to have this as an export option

Pick up a mackie big knob for cheap, and control your monitor volume with hardware. Keep your software/hardware volumes at unity. 

Resonant Serpent
Pick up a mackie big knob for cheap, and control your monitor volume with hardware. Keep your software/hardware volumes at unity. 

I already do that with a Samson C-Control.  Works great.

BobF
I can fully appreciate the OP.  I think what is being asked is, "Can export be done 'pre master fader'?"  I would love to have this as an export option

You can easily set this up yourself can't you?
 
Just insert a buss called Pre-Master and route all of your other busses to it.
 
Route the Pre-master to the master.

Bristol_Jonesey

BobF
I can fully appreciate the OP.  I think what is being asked is, "Can export be done 'pre master fader'?"  I would love to have this as an export option

You can easily set this up yourself can't you?
 
Just insert a buss called Pre-Master and route all of your other busses to it.
 
Route the Pre-master to the master.

Great idea!  Even easier, route Master to a new stereo bus with the desired hardware output selected.  Then in the bounce source category dialog, select buses > Master
 
Only one additional bus routing selection this way.  Save as a preset and we're off and running.
 
Thanks Jonesy ... sometimes we just need to stand back a little bit