IMHO if insurance isn't a legal requirment, or the cost is good value compared to potential claim amount don't bother.

All cars will pick up knocks and dings and you can end up chasing your tail having them sorted out. Save your cash in an account and spend £100 when you come to trade or sell to on a valet and polish.

This is probably more of a concern to those who have the cars for a set period of time on some form of pcp/lease agreement and are worried about large bills to correct damage on return.

Like all things judge what your previous damage experience has been and where the vehicle is to be driven and parked, if the wheels are massive with low profile tyres then kerb damage is very likely (is that covered because fancy wheels cost fancy money to refurb) and check what's in the small print and check what are other 'genuine' users saying of their experiences.

Our cars are older and we have a good relationship with a one man and his dog bodyshop, so every few years if various things need doing we'll drop the vehicle off and get them all done, we would be way out of pocket paying for insurance cover of this type.