Did you ask about a carfax report for the vehicle? If you are getting it from a dealer, they might have it, and it would be easy to see a major rollback. (I'd disregard a minor one... I think there was another VX sold recently where Carfax reported an error of something like 50 miles. Probably more of a typo at the DMV or something.)

If you have to get the report yourself, it's about $30 I think.