Today I made the mistake of driving to pick dd1 up from school - she had to go to a party at 4 so I thought if we drove we could shoot back home and do her reading/get changed before we went.
I parked, picked up dd1 and got back to the car to find loads of cars parked along the middle of the car park so I had about five cars boxing me in. I settled back for a good long wait , then saw the car in front of me moving. Suddenly I saw a little boy in dd1's class (reception) 'driving' the car - it picked up speed and smashed into anothher car with a huge bang.
I went to get the mum and a few of us gathered round - then I will admit I sloped off (a combo of having to go and also being soooooooooooooooooo furious with the mum that I was about to say something and couldn't bear being 'the confrontational one')
god knows how it went so fast so quickly, I don't think he turned the engine on so he must just have taken the handbrake off.
It happened outside my Mum's house too. 3 year old left in the car while his Dad went to put somehting in someone's porch...only took moments for him to get out of his seat belt (easy once they are in a booster type seat rather than 3 point harness of car seat), take the handbrake off and send the car hurtling down the hill towards the quay. HIs baby sister was in the baby seat, too.
A workman actually managed to open the door of the moving car and pull on the brake.
Horrifying. Same thing happened in our street. A neighbour's children were playing in a 4x4 when they released the handbrake and the car went careering down the road. Thankfully, it crashed into another neigbour's car. If that car hadn't been there, the 4x4 would have gone down a 45deg grass bank.
Also, a friend's ds once meddled with the radio's wiring when he was allowed to play in her car and the car went on fire.