The cars are certainly not the only problem, but I have heard that some manufacturer's cars are absurdly easy to steal.
A coworker used to have a nice Ford diesel truck. He left his truck at a gas pump at the Buc-ee's in Wharton, TX. As soon as he got inside, some guys that had been parked off to the side went up to his truck to steal it. Someone else nearby realized they weren't the same people that drove it up yelled at them and they left. However, it less than a minute, they had jammed the door lock and plugged something in to flash the computer which would allow them to start it without the key fob or use something else. My coworker had to pay a good bit to get the dealership to reset the computer so he could drive it again. Ford trucks are high on the list of stolen vehicles and that Buc-ee's is on HW59 heading straight down toward the border.