My parents were indeed, just like yours. They're very pre-cautious. They said no to me getting one. I done my research, rang up a few LEGAL and local tracks and to check when there session are on. I even came on here and had a few tips and advice before I bought one.
A few days after my holiday I went out without my mum and dad knowing, paid for the bike and the kit WITH my OWN money. I then went home and a few days later I had a guy from our motorbike shop knock on the door and my father answered the door. He then seen the bike and he we are!
He was pleased that I had done all of this by myself and handled it in such a good manner without hassling them and here I am today. With a bike, great parents who will drive me to local tracks and everything.
Just do what you need to do buddy.