Jack, it runs from Thursday through Sunday. The best day to get good deals is on Sunday when everyone is packing up and doesn't want to take everything with them, but Saturday is the day with the most cars/people. On Sunday there is usually a small LBC show gathering there too.
Scott, Autofair is the annual redneck gathering of hotrods and muscle cars out at Lowes Motor Speedway. There is a lot of vintage stuff there as well. There is always a bondoed up LBC or two for sale for twice its normal value. They have a HUGE swap meet, with loads of cars, parts, tools, and memorabilia. The nicer cars are usually parked all the way around the track with for sale signs on them. There is a decent sized auction and there is also a "feature" tent full of specialty cars or featured marques.
My dad and I have done the full show and field walk once in all the times we've gone, and it was in the fall when the show is slightly smaller. We started early, stayed until they closed, and did not waste much time. Even then, we barely covered all the paths, and we were dead tired. We usually skip a swap field and are able to do everything else. It is a HUGE show, albeit with mainly American stuff.
Terry, will you be around your GTs on that day? We will have to stop by and say hello to you guys if we see your cars.