I think the way to go is someone (Steve P?) to get a list of names together (from both this site and any other's that people may be on) and send a letter to VW in writing saying that we want a postive conclusion to this or we will be forced to take this to Top Gear, Fifth Gear, Which, Trading Standards, Police Complaints Commission, etc etc.
If this doesn't get them going then I think the next stage would be to take it to the above mentioned authorities and try and shame VW into action.
This is my first VW and the way they are treating people it may very well be my last!