Alarms, anti theft, and recovery devices

Well, I guess it was my 30 seconds this time. Every 30 seconds a vehicle is stolen and one of my many scooters was plucked off of my truck. Other than a steel cable how one secure it to a vehicle. Do brake caliper locks work? Is there GPS for bikes. Most transceivers need a 12 volt battery like on a H-D or a Honda or something that uses a starter battery. I just spent the spring putting a dual charger on the XM-3100 so I can go another round before noon.
What is the best way to keep a Vectrix, EVT, CuMoCo, and other electric bikes safe? Can a Xena disk lock be cut with a plasma cutter? Or do you just buy a new disk? How can you prevent a theft of a scooter? right now I keep the VX-1 in my Living room or garage during the spring and summer. During the day it still is outside where every one knows it is a maxi scooter. I just never thought it would happen to me. Being it is metric stuff on a bike I guess I should use a 9mm with 150 grain?