Rear mechanical diff lock available for GC?

[HugoFar]

The California 4MOTION has the option of fitting a rear mechanical diff lock. Does the Grand Cali get this option too? I don't see it listed in the VWNZ spec sheet. Thanks.

 

[AndrewCook680]

I got one on our UK GC 680 4motion - it was an optional cost extra

 

[SpuffingtonMe]

I‘d also be very interested if it could be retrofitted. My 4Motion 600XL performed brilliantly on some very hilly and wet campsites in France last week but the extra reassurance of a diff lock would’ve been useful.