I can not tell you about the one in Tulsa, but I can tell you about the Fling.
Do a search here on DVSF and check out
www.dvsf.com (probably not updated for this year yet). You should find LOTS of talk and pictures.
The Double Venom Spring Fling (this year is number four) started over some chocolate cookies. Then there was some competition about who had the best desert and the next thing you know you have a little picnic that turned into hundreds of cars and sponsors with the proceeds going to 'Team Jenny' Cystic Fibrosis. Jenny is Dave Smiths daughter, one of the owners of Factory Five, who has CF and the money is given to CF in her name ($106,000.00 last year).
The "Fling" is a strickly fun, Cobra event. There are no races. Although we usually have a little drag strip, burn out type places and an autocross these are strickly for our amusement not for competition. There are no trophies or awards. There is cruising, some shows, picnics, parties, auctions, LOTS of mixing and that sort of thing. We get together and give the public rides and raise money. The Fling is for Cobras 'only'. I put only in parenthesis simply because there is the occasional Daytona Coupe, GT40, etc.
Basically it is a three day plus long social gathering/party. I wouldn't miss it for the world!
With out being overly long winded I think that sort of sums it up.
Rick