Im a little confused regarding this so hoping someone can bring some light to this for me.

I have a 01-plate bugeye impreza GX, when driving it feels ok but if I coast along or keep the speed low but steady say a rolling speed between 10mph to 25-30mph the whole car shakes and rocks side to side, it shakes you on the seat like people are rocking the car. Someone suggested the knock sensor which I expensively bought from subaru but not fixed the problem. Any ideas are fully appreciated

Chris.

 

Does it do this when coasting in neutral?

 

Yep, coasting and steady low speed throttle

 

So its probably not engine related. Id go with a square tyre. Jack them up one by one and spin the wheel. Youve probably got a deformed tyre