The 2001 WRX in Australia came out with only the standard immobiliser installed. Subaru Australia are upgrading for free the system with the Keypad Immobiliser that is in the 2002 WRX.
The Alarm upgrade is normally aus$1100 and they are offering it with the immobiliser upgrade for $550.
How good is the factory alarm system?
What features does it have?
p.s. Well done to Subaru Australia for fitting the upgraded immobilisers for free to all 1998-2001 WRX's to help with insurance problems.