An article published by confused.com looked at the figures from the stolen vehicle recovery service "Tracker" which showed the top 10 stolen cars using their system.
It appears that Range Rover and Landrover feature frequently with cars being stolen to order and being shipped overseas. Many of the high end vehicles had keyless entry and the article looks at the things you can do to protect your car.
The main suggestion was using a Faraday Pouch so that theives couldn't amplify the signal, you can find an example here on Amazon.