Wheel Clamp or rely on Cali Alarm System

[Daz777]

So then, having had two cycles stolen from my locked garage within the last few months, I have to say that I do feel a little nervous that my newly purchased Cali now sits out on the drive protected only by it's door locks and VW alarm system.
Do most owners rely on their vans alarm system or do you fit wheel clamps? If fitting wheel clamps what type would you recommend? Or are there better security devices than wheel clamps? Cheers, Daz