Keyless entry systems are particularly susceptible to theft in the UK, affecting not just Kia but also Land Rover significantly. However, I am uncertain if any type of protection exists for non-keyless autos. Game Boy assaults (do a Google search) have proved problematic, but their prevalence remains uncertain to me.
I like a visible deterrent; so, a Stoplock is likely as effective as any other strategy. Regrettably, if somebody want to steal your vehicle, they will devise a method to do it.