I was given a bike seat by a friend and my 2 year old can open the clip on it. I have looked for extra harnesses/clips but can't find any so think I need to get a new seat with a better clip. I would be really grateful for any advice about bike seats with childproof clips or any add-ons that could make it more secure. I think it needs to be one that goes on the back rather than in front as he would probably try to 'help' me steer if he can reach the handlebars. Thanks very much.