We get regular information security updates at work, it's not so much the problem of cloning, as you say they can find an RS3 on autotrader but all the same it would be a hassle if it happened to you. What it does is allow them to start building up a profile about you and your car via small snippets of information taken say from this site, things you write on facebook, the lat and long information from smartphone pictures etc etc. The security guy demonstrated how easy it was to find out a mass of information about one of the younger members of staff (they had given permission for this) who had open profiles and comments about future events/locations etc. I think it's worth keeping that in mind when you post stuff online and just being sensible about it.