The SBS hosted Top Gear Australia website has recently published a working drawing of their test track. The location is Camden Airport, Sydney—follow this link for the Google-Maps-eye view.
Currently a right-hand drive Ford GT holds the record for the fastest Power Lap time at 1:08.80, some six tenths quicker than a Nissan GT-R (speed limited). A full list of lap times can be accessed on Wikipedia.
Source: SBS