I've thought of this but decision will probably depend on the Insurance that I take out (Cali due March).
From quick look I've had ALA seem good with good reviews & competitively priced, I've asked a few questions and there customer service team is pretty good, but as always you only know how good the insurance is when you try to claim.
They do a vehicle replacement plus (what I was looking at) - 'A Vehicle Replacement Insurance policy will, in the event of a Total Loss claim, either pay the difference between the Comprehensive Insurance settlement and replacing your vehicle new for old' rather than invoice based.
You choose the value of cover that you want to protect yourself for the term of the cover (up to 5 years allowable) Rough guide is £30k worth of cover on a Cali for 4 years was about £340. So the longer the policy the bigger the value you probably need to take out... being honest £30k on a Cali is probably too much but not sure how Insurance Co's would value on a total loss and difference is extra protection didn't work out that much more on the premium.
Seems as though you can take out the policy up to 1 year after delivery (Might be worthwhile if you are covered in the 1st year by your Insurance Policy but would need to check this).
Found a link to buy with 10% off until end of March
http://www.ala.co.uk/honestjohngap/ code is
HJ65
Appreciate any thoughts from others on this but as I said we'll probably utilise Insurance Policy in year 1, but still have Insurance to sort (another bit to research!)