What are the differences between the 99 and 2000 XK8's? The dash is different in the 2000 with navigation...but other than that are there any significant changes?

 

There is no difference in the Dash. The Standard Dash with the 3 Gages is the same for both years.

The Nav Dash is the same for both years.

For XKRs:
In the U.S. XKRs were first available in MY 2000. The Nav was optional for MY 2000 only. 2001 and newer U.S. XKRs had the Nav as Standard.