It may be, I don't know for certain as they face lifted the A4 in 2002. There are some B5s and the rest are B6's. Reading that site a little more after I posted it made it seem there will at least be options for some other cars.
The newer cars are really more advanced than their predecessors. In an almost shocking way with how everything is controlled. The car is basically is a bunch of little computers inside a giant case.

The MFD on the newer cars is much more elaborate than it was on the B5's. I think the controller parts will work for the B5 but the display in the dash probably will not work.