EcoxA

I recently bought an xA with no key fob and just thought the owner lost it. As I've read now, these cars DIDN'T COME WITH KEYLESS ENTRY!!! What the heck it's a 2006. Oh well, my fault. So, I have access to 3 1st gen scion xBs for parts at a junkyard. Does anyone know if I can simply pull the keyless module out of the xB and put it in the xA? I found a toyota security system for $114 which I could do but I want to go even cheaper, and I only want keyless entry with a real toyota key fob. I don't really care about the security aspect of it. Anyone know what my options are?

Thanks, love this little car!