It all depends on the wine. More complex wines and different varietals age differently and of course how a wine is stored make a huge difference in how a wine does over time.......unfortunately sotrage is only one of the factors in the ability of a wine to grow and flourish vs. degrade over time.
For instance your 1999 Mondavi Cabs the drinking window of the reserve (more complex wine) is fine and the wine may actually not even be ready yet as the drinkability is 2015-2030 so you are good there!!
On the regular Cab (less complex) it's drinking window was 2005-2010 and may be past it;s prime.....according to recent reviews on that wine it is suggested that it may be a little past it's prime but still drinkable. I would suggest that you need to drink this one right away.....this evening probably to avoid any further degradation :D
Note: These observations come from "Cellar Tracker" which is one of the most widely used cellar management Apps....it's shareware so anyone can get onboard for no cost and for a small contribution get even more functionality and reviews.....
www.cellartracker.com