What's the current problem? If there's a vibration you're trying to track down, you at least have an additional way of troubleshooting some of the potential problem parts, and that's by swapping parts from the other VX in your garage.
Granted, it depends on the part in question as to just how hard/time consuming the swap may be, and the fact that the process effectively takes both VX's out of commission for awhile, but that's just time invested, and could maybe save money wasted. (I don't know about you, but there's fewer things more frustrating when it comes to car repairs than having new parts thrown at a vehicle in the "hopes" it will fix the problem.
Any specifics of the current problem that could help everyone here offer a few possible suggestions for fixes?