Question regarding the default file manager in XFCE

[Vladimir Nikšić <vniksic@xxxxxxxxx>]

I'm using xfce wm. I rarely even use a file manager, I do things through 
the console almost all the time, but sometimes I need a file manager, 
makes some things easier.

Thunar as a file manager is OK, but nautilus is a lot more powerful, has 
decent tab implementation etc, etc, doesn't really matter. I went to 
settings -> preferred application and selected Nautilus under File 
Manager. This works only to the extent that when I click on Application 
Menu and then file manager, Nautilus starts up.

I would like it so that Nautilus starts when I click on a directory or 
some sort of volume (loop mount, usb stick, whatever, nfs share) on the 
desktop. Instead, thunar always starts, which kinda defeats the whole 
purpose of the preferred application setup?

Am I asking something that's technically difficult or maybe there's a 
good reason why this can't be done?

Thanks!