I noticed this whine sound when in the driveway and the music off. The sound is like a supercharger or a power steering pump that is low on fluid. The sound gets higher pitched when accelerating in drive or neutral... multiple other 4runner owners have reported the same noise on 5th Gen 4runners with different mileage ranges. Toyota says that it is a normal operating sound, but some 5th gen 4runners do not make this noise... so it can't be.