I know this is a pretty narrow range of caddies but the Impala SS Club of America is holding its 2007 Nationals in St. Louis this year in a couple weeks.
The club is made up of owners of the B-Body platform from GM which includes the Cadillac Fleetwood, Caprice, Impala SS, Buick Roadmaster and associated Wagons. This is an incredible group of folks that have a true passion for their cars and an honest desire to help other owners. Some really crazy enthusiasts.
If you own a 1994-1996 Fleetwood (B-Body) and are interested in seeing some beautiful cars doing everything from showing, drag racing, auto-x or road racing or want to join in, take a look over here: http://www.isscanationals.com/