Im not sure how to describe this and its something I have managed manually for a few years now... When a track (project ) ends, sometimes it take time for the last notes to decay, which will be longer than the clip. This will result in the fade-out being cut off on bounce.
 
To overcome this, I extend the last note clip until it finally decays. Freezing the track will not help either. So is this the method that most Sonar users use or am I missing something?
 
 

Right-click the Freeze button, choose Freeze Options, and set a freeze tail duration. Note that Track FX has to be checked for the tail duration option to work.
 
EDIT: When bouncing/exporting, all you have to so is select some additional time in the timeline.

Thanks... so is this the best method not to loose the decay/fade-out at the end of a track? I would like to think the this would be in the bounce option to make sure it captures everything?

I've been extending the length of the final Midi clip(s) for years to preserve the natural decay of the instrument(s)

I usually just select an extra measure or two to bounce. Another option is to have some inaudible event in the project out past the end of the last MIDI event. This could be a MIDI controller or a node in an automation envelope.

oh yes, I do all those things but when you forget..its a pain