big hug for nykkie, honesty best policy, well done for owning up to it. someone knocked my wing mirror off in tesco's car park once, bless him, he waited till i came out to tell me, i was so impressed i told him not to worry about it and call it karma, honesty is good and deserves some reward. i dont think that insurance is invalid if you're on private land, they would have to draw our attention to that if it was and i;ve never noticed it on my policy. however, unless the damage is very bad or their car is very expensive, for the sake of having it all over in a day i'd protect my premium and my sanity and offer cash to cover the damage. dont involve your insurers until you have too. :-)