Just drove into the back of someone's car at low speed. It doesn't look like his car is damaged (his tow hitch took the brunt of it). If he doesn't want to claim off my insurance (I've offered to pay him cash if it's less than my £100 excess), do I have to tell my insurance company and dent my no claims bonus? DH has already bashed out the bumps and fitted a new numberplate on ours and reckons he can fit another bumper for about £25.