Probably using a gps jammer, thief's are getting more high tech huh?
well a combo of security gadgets, for example
GPS tracker, immobilizer, steering lock would make it very hard for the thief to steal your car but it's not thief proof.
My perdana v6 had a steering lock but it was successfully stolen, my mistake was parking it outside a condo because no visitors were allowed to stay midnight without permission.
To reduce the risk of theft, always park in safe areas. Always park inside your house compound if possible, if you go to eat at a mamak, make sure you park your car where you can see it,
always park at a paid car park. No point saving a few ringgit which risk your car getting scratched, damaged, stolen, etc