I had, keyword had, customized warning sounds for speed cameras. With the upgrade to a new phone, and Android version, I've lost the ability to put my sounds in. The files were com.mapfactor.navigator/files/navigator/warningsounds/scout_100 (plus 500 and 1000). Now the directory is hidden.
I would ask that you add the files to the backup file, then I can off load that file, replace the *.wav files, upload the backup file and do a restore with it.