Finding leak in air suspension

[Stuarta]

Anyone have any advice on how to find the leak?

I'm still a newbie A8 owner and all was well until this morning when I had the dreaded flashing icons - this is what vag-com said:-

Address 34: Level Control Labels: 4E0-910-553.lbl
Part No SW: 4E0 910 553 H HW: 4E0 907 553 F
Component: LUFTFDR.-CDC H06 4480
Coding: 0015510
Shop #: WSC 02313 785 00200
VCID: 2855E99BE263

3 Faults Found:
01583 - Leak in System Detected
000 - -
Freeze Frame:
Fault Status: 11100000
Fault Priority: 3
Fault Frequency: 74
Reset counter: 55
Mileage: 60487 km
Time Indication: 0
Date: 2011.12.05
Time: 14:38:24

01577 - Turn-Off due to Over-Temp
001 - Upper Limit Exceeded - Intermittent
Freeze Frame:
Fault Status: 00100001
Fault Priority: 4
Fault Frequency: 24
Reset counter: 95
Mileage: 61176 km
Time Indication: 0
Date: 2011.12.29
Time: 11:02:55

01400 - Suspension Level Control
002 - Lower Limit Exceeded
Freeze Frame:
Fault Status: 11100010
Fault Priority: 2
Fault Frequency: 2
Reset counter: 55
Mileage: 61581 km
Time Indication: 0
Date: 2012.01.15
Time: 11:27:51

I tried clearing the codes but they all came back straight away.

I'm assuming that the over-temp is due to the compressor being taxed to overcome the leak - question is, how to trace the leak?