I popped in to visit a friend and was there for 10 minutes. When I left the house, I got into my car, checked my rear view mirror and side mirrors and continued to check for cars and persons as I backed up my friend's drive (private property). I got so far and heard a crunch. I got out to find a bike under my car. Whilst I was in my friend's house, a neighbouring child had left her bike directly behind my car. The child's mother insisted immediately that I pay the price of the bike (£130), to which I have agreed. However, I am interested to find out - am I liable? Is the bike owner (parent) responsible in any way?