DRIVING DOWN THE ROAD WITH CAREY RUSS 2010 Volkswagen Jetta SportWagen TDI First, a definition: Cult car: a non-mainstream vehicle supported by a small but rabidly fanatic group of owners who would never even think of buying anything except the new version when theirs finally gives up the ghost. Here in the USA, small wagons are cult cars. And diesels are, so far, cult cars. So, put the two together and while the result will have a receptive audience, it likely…