I have a 2002 wrx 5 speed, i paid 500 for the subaru starter and upgraded alarm.
The alarm has no shock sensor, or glass break sensor. If you want, I will sell it to you for $150.00
I now have a Autopage 850lcd two way starter/alarm. it has everything you need, and it tells you if somebody is breaking in.
bottom line is, buy aftermarket, if you want to have a better alarm, and longer range.