This is an old story.

About a year ago, I had someone who smash through my car's right side-mirror.  I called up NRMA and asked about their policy "if it's not your fault we won't charge you excess" which they were heavily promoting at the time, they informed me that I would lose my no-claim bonus for next year.

Which just means I'll pay the money later when I renew the insurance.

I ended up calling off the claim and just replaced my mirror from a second-hand parts store.

Mirrors aren't that expensive to replace, but I've had this insurance for 10 years and each year it's cost me about 10% of the cost of the car, if I totaled it.  In hindsight I don't think I needed car insurance at all.