I know it's been discussed many many times, just wondered if someone could suggest to me again why I'm having problems...

Every time I go over a speed bump I get the most horrible creak from (I think) the back of the car).

When I bounce the back of the car from side to side I get the noise and it seems to be coming from both rear wheels.

The other day, when getting new tyres, I asked the guy at Formula One to check the suspension and he told me the bushes are fine (but not sure whether to trust him or not).

Anyone got any advice for me? I don't want to go to the hassle of replacing the bushes, only to make no difference...

I saw a video posted from here a while back, which showed how to check rear bushes, by grasping the top of a rear wheel and yanking it outwards to listen for the clunk. When I do this there is slight play on both sides, anyone know if this is normal, or related to my creaking problems?