That wouldn't work under UK law as no person in thier right mind would deem that reasonable.
I deem that reasonable, going back to same example used above, in my McLaren F1 (or even Toyota 2000GT - only 337 ever made) is written off - what does the current law give me in return - because chances are it is not going to be able to return me to the previous position of owning the said car in a same/similar condition.