The steady, back-and-forth motions of a 1979 Ford Econoline van sent 'a clear message' to local resident Paul Dunne Monday, discouraging him from knocking. 'I needed a jump-start for my car, and the closest vehicle was this van,' Dunne said. 'I was about to knock on the back window, but when I noticed that the van was clearly rocking, I didn't bother.' Dunne instead received assistance from an adjacent, non-rocking vehicle. 