IMO opinion this is pointless and i have not taken this out on my car. One, all car insurance is new for old for the first year anyway (if you buy brand new and are the first registered keper) so straight away you are only gettin 2 years cover for your money. Two, (for me) i rarely keep cars for more than about 2 and a half years so this would reduce the benefeit down further. and three you would have to an awful, awful amount of damage to a new car costing 20-odd thousand - the typical threshold is 60% which means on a 20k car (is there many audis bought for less than this brand new??) you would have to do over £12,000 worth of damage to write it off - thats a hell of a bang and a mess of a car, and probably a very hurt driver!
It would be interesting to know the exact figures for this scheme - i reckon out of every 1000 brand new cars sold about 20 would be written off in first 3 years - this is a hell of a profit! My summary: Its a tiny tiny benefit that serves more for making dealers money.