Not many people know this but im going to break down and define each part of the cluster part number:
* 1T0 920 973 AA Z0_ * is the example arrangement.
1T0/2K0 (For Touran / Caddy)
920 - I'm not sure on this but pretty much all clusters have this
973 - these 3 digits are explained below
The first digit (9) indicates that MPH is units displayed on the speedo ( If there's and 8 instead then KPH)
The second digit (in this case 7) represents one of 3 levels of computer:
-if there is a 5 then its a LOWLINE (no computer)
-if there is a 6 then its a MIDLINE (small screen trip computer with basic functions)
-if there is a 7 (like in the example) then its a HIGHLINE/MFA+/FULL DIS... (with full size screen and trip computer and many other functions and settings.
The third digit confers a number to the type/version of immobilizer the vehicle uses (for the approx date ranges):
"0" is for early 2004
"1" is for late 2004 to mid 2005
"2" is for late 2005 to mid 2006
"3" is for mid 2006 to early 2007 (as in the example)
"4" is for early 2007 onwards.