Was this an option on 04 and other 4th gen? I have been enjoying my runner and noticed that all I have on my v8 is the center diff lock. Was just curious because my parents 98 limited had a rear diff lock and it help me many of times getting out of sticky situations.
The only 4th gen to come from the factory with a rear diff lock was the 2009 Trail Edition. There are a few aftermarket options though if you really want one, its a pretty solid capability.