I have had lots of "flippant conversations" about this, mainly because many of these conversations are based on (understandable) fear rather than facts.
But you are essentially managing your own worry rather than real statistical risk. If you determine that is worth you bolting deterrents onto your Cali, or having to press a half dozen buttons every time you start up, that's up to you. They are not really stopping your Cali being stolen, because it's is highly unlikely that will ever happen (see key caveats), but they may help you sleep at night, which for you, may be worth the cost and faff.
The facts are:
- Thefts of new cars are very low. Most "vehicle crime" according to the ONS is theft from (not of) unlocked cars.
- Since Thatcham security was introduced it's very hard for anyone that is not a hardened professional to steal a car. Even for them for new cars it is a planned in advance professional job. We used to hire "white jackers" at Nissan to test them for us.
- A Cali has the highest level of Thatcham rating. Even more so because it is not keyless start.
- It is impossible to steal a Cali without the key. Impossible. The only way to do it would be to lift it into a low loader or try and tow it away.
- Key security is therefore more important than anything else, IMHO.
You can fit Ghosts, Bears, Clamps and many other things - but, they are to put your mind at rest more than to stop theft. IF you secure your key. If you don't want to secure a key, then get a Ghost. If you don't secure your key or want a ghost, get a tracker. Someone made a great point they would not want their Cali back after the scroats had been done with it. I'd tend to agree. It's why I pay insurance.
We store all our keys in a hidden faraday box (even the Cali one). Our estate had three high end cars stolen in one night (3am) about 3 months ago. Highly professional crew, using key signal theft from owners who had their car keys hanging up within range - usually in the kitchen or by the front door. Two Beemers and a Merc. They were in black head to foot, on everyone's ring, and done in < 10 minutes. Highly targeted and likely scouted days ahead. A crew that determined, take more than a ghost or a yellow wheel clamp.
So, IMHO (again), it's about managing fear, not about the reality of a Cali being stolen.