Hi Dan, I am reasonably close(ish) in Purley- you mentioned St Helier the other day, I used to live in Carshalton and still have in-laws over that way. I used to post quite alot on 'Was it you?' but never had any luck. I now just flash my headlights at other A2 drivers and hope that if it was someone on the forum that they will ask if it was someone here...
One thing I have done instead is print off the small flyers that are at the front of this website and hand them out to A2 owners / leave them under their wing mirror in car parks. To my knowledge no-one has joined / posted as a result of that either...their loss!