Cleansweep or Lc8i on JBL w/NAV

I have been reading this forum very thoroughly and have also read some of the threads on adding an amp on the 2nd generation Prius. I read on one of the threads that person added an aftermarket amp and sub using the lc8. I am wondering has anyone tried to add an aftermarket amp by tapping into the rear speakers and using the cleanssweep or the lc8i on the 2010 with nav? I plan to keep the nav definitely. Thanks in advance.