[silverbmwz3]

"as your insurers would replace the car with new"

Not necessarily...worth checking policy wording. I found mine wouldn't, or if they did, wouldn't include the 5k+ of options in that. I found one that would. Many will just give "market value" which even in first year is a considerable chunk less than new cost.

I hadn't thought of the excess in the first year, but then it is probably a money swap pound for pound with the amount of the premium they would charge for Gap insurance.

You mention risk a few times, but this doesn't seem to be about protecting risk to me. "I'd like to protect against the risk of my 3 year old car being stolen/written off by buying a policy that replaces it with a new one" ?! FULLY COMP INSURANCE is about risk, this is about getting you to a better position than you were in when you had the accident/theft. Generally insurance doesn't do "betterment" but these policies seem to be just that.

To me they are a bit like extended warranties.... generally don't touch them with a barge pole as they are a money making scheme.