As long as the vehicle has some type alarm system fitted well then the perfect solution to cover literally every other method of theft is to have the ghost system and a decent tracking system, this covers all angles of it been driven away, dragged away or lifted onto a truck. Have you had the new software on your Focus Rs, if not contact your installer to rectify the issue they had with the focus last year. It'll be free of charge.
Before I sold my focus last year the installer I use came out and reinstalled it with the update and new features.
As Mentioned before it shouldn’t be the one product you use but it should form part of a multi layered approach. With the aim to scupper the chancers all the way through to the more professional scumbags. There ll always be another car ‘just around the corner’ that doesn’t have any protection and that is no bad thing as far as I m concerned, that apathy to security is a benefit to me.
I have 3 - 4 systems in place with my current Range Rover, as they are notorious for going walk about, infact one of the most common sights round here is Range Rovers with steering locks fitted.