I'm torn between two:
Serious / hardcore wheelin(catergorised)
AND
Socializing
Although the wheelin' always wins out in the end (my vote)
As mentioned , onsite site track/s for the nutters is always fun to watch/drive
... you'll also find that alot of the bigger built don't do the mud : mud = bad
Lesson learned from CampCoffs: have a tilt-tray on standby