Gregg--- My best advice is to KEEP LOOKING!!! Run away from those poor VX examples, as those irregular sounds are probably the main reasons they're up for sale. Those sounds you hear are not normal and are an expensive can-o-worms just waiting to be opened.
Be patient; the right VX is out there somewhere, and you'll immediately know it after a thorough test drive and a mechanic's inspection. Heck; it took me over 7 years to find mine, so just keep lookin'.
This isn't a thread asking advice to buy or not. (I would place that kind of thread in VX Talk.)