I England they call it an Auto Test or Gymkhana but here in the USA we tend to call any event in a parking lot or large area with cones an Autocross. Most auto-x her in the USA are more of a challange to the ability of the driver to operate their vehicle around a predetermined course in the fastest time without hitting any cones (usually adds 2 sec. for each cone hit) so it is more of a control test than a highspeed event usually.
Here is a clip that is one of my favorite of a GYMKHANA / AUTO TEST in England in a small parking lot....wish I had the drivers abilities.
Defination of a Gymkhana from Wikipedia:
"Gymkhana events are time/speed events events (four our purposes here,) in an automobile. There can be obstacles such as cones, tires, and barrels. The driver is expected to maeuver through the predetermined "track" performing many different driving techniques. What separates gymkhana from your traditional autocross event is that in gymkhana drivers are required to perform reversals, 180 degree spins, 360 degree spins, parking boxes, figure 8s and other advanced skills. Also drifting is encouraged where helpful/necessary. Really though, you can consider any event a Gymkhana which has a starting point, a finish line and some sort of "obstacle" to get through, around, or by, and is timed!"
Autotest - Christopher Evans in a Westfield on Yahoo! Video