I did a quick search and did not see this outlined, so I figured I would post this up here.
In the third gen, there are two versions of the center console. The most obvious difference is that one has 1 cupholder, and the other has 2. There are a number of other differences as well, which I will outline here.
This is a picture of the two different kinds side by side. Here you can clearly see the differences in the top. The black one was used for 2000-2002 cars, the beige one was used in the Late 2002-2004 cars. The square hole on the double cupholder version is where the coin holder or heated seat switches would go.
The top plate is specific for the center console. This is best shown on these two pictures. Again, this is the earlier 2000-2002 version, you can see where the top plate meets the console at about a 45 degree angle.
This again is the Late 2002-2004 version, where you can see that it meets up at nearly a 90 degree angle. It also has a thicker/taller armrest.
Here are the two side by side, with the 02-04 in the front. It is quite obvious that the two are vastly different, and you can see the thickness difference of the armrest cover as well.
So, the moral of the story here is.. if you want to change a single cupholder for a double.. you will need the entire console. Also if you have heated seats, be aware that the switch locations are different between them, and your wires may not reach without modification.