OK, the tours are booked (it ain't much anyway).  But you're on the guest 
list for a complimentary OPUS tasting (see previous note).  OPUS is across 
the street from and just south of the main Mondavi winery.  When you get 
there, check in with the concierge, who will have your name and will set up 
with the complimentary tasting.  It gets real crowded sometimes, which causes 
them to close the gates.  If that occurs, you simply need to buzz the 
intercom and give them your name and they'll let you in and set you up.  You 
should really do the tasting----the wine is simply awe-inspiring and it's a 
cool place.  Finally, they're open from 10:30-3:30.  Later it gets, crazier 
it gets.  I suggest you try to get there around 11:30, which will ensure that 
you get the attention you deserve.

Have a great time.

Best,
Jeff