We have a habit of entering the Birkett Relay (http://www.750mc.co.uk/formulae/birkett.htm) a 6 hour team endurance race for between 4 and 6 drivers, held on the Silverstone Classic GP circuit on the last weekend in October each year. The idea is to have an end-of season jolly with as many of us as possible, it's a good laugh, and fun racing because there is such a huge range of machinery there so we get to play with stuff we're not used to. As there is such a range (from sports prototypes to Smart cars, sometimes) it is run on a handicap basis - you submit lap times for all the drivers in the team, in the cars they propose to drive, and your team is allocated a number of handicap laps. So anything can win, even if your cars are not hyper-speed prototypes. With 70 teams, each with 4-6 drivers, it's a massive event. There are always more Caterham teams than you can shake a stick at.
We go there for shits & giggles. It really is fun. But we only went and came second in class this year 5th overall, too
Oh - you might be able to see a piece about it on telly sometime next year, btw. A certain BBC motoring show was there filming. And taking part, in ridiculously unsuitable cars.