hmm, hate that bouncy thing, shaking the inside of the car to death. my astra coupe used to do it when i first got it. think its sometimes to do with wrong tire pressure or rubbish tires, bouncing instead of spinning. when i changed the tires to zz3's instead of bouncing & shaking, it would just screech up. stiffen up the suspension aswel. not that you wanna be smoking up your tires on purpose,lol.