hey guys im kinda new to scion and i just 04 xA and was wondering if i can use 04 xB factory alarm on my car and also if factory alarm is also gonna unlock my car with factory remote?

I dont see how it could hurt anything..its just an alarm system....the wiring shouldnt be any different.

Welcome to the family! Don't forget to check out www.xateam.com too :D

And as far as I know, everything should work fine.

welcome dd!!! Don't know about the alarm, but you could call a dealer and get the part # for both and see if they are the same...

Yes you could but you don't want to because it's WAY too overpriced. If you're willing to spend what it costs then you can get something much nicer. Otherwise you can get similar for like under $100 I believe.