If you try to use Sonar's synth rack to automate Kontakt instruments you may be frustrated to find parameters are not available for automation.
The process for assigning host automation is the same as the method I described for Komplete Kontrol on the Hardware forum.
You need to open the auto pane in Kontakt and select the host automation tab.
Drag a host automation ID to the knob you wish to automate on the instruments GIU. When you have done assigning automation save the NKI.
Now when you go to the synth rack these parameters are exposed for automation.
If you have been following Craig Anderton's tip of then week you will know that you need to undock the Sonar browser in order to see the synth rack.