SEAT Toledo, based on a Golf mark 4 so rear beam axle, mcpherson struts up front. All standard fairly new suspension, all poly bushed. I have a very odd behaviour going on, and I'm not 100% sure what could cause it. I'd appreciate people's views;

1. When I accelerate the car pulls to the left. If I have the steering wheel held in position, I'm on the white line after a second or so. If I leave it to follow it's own accord, it'll also start turning left.
2. When I engine brake, the car pulls to the right. Again, if I hold the steering wheel the car will drift to the right, if I let go altogether it'll do the same.
3. If the car isn't accelerating or decelerating (on cruise control for example), it goes in a straight line.

I'm guessing either something is loose, worn or misaligned, but I'm not sure what would make the car go different directions on the change of speed. The only thing I can think of is the rear track is changing as the suspension compresses or extends with the change of speed.

Check the polybushes in the lower wishbones. Polybushes rarely last as long as the manufacturers would have you believe, especially the rear bushes on the Golf which take a battering and don't even last very long in rubber form.

also have a problem with the rear bushes

Front lower arm rear bushes

Agree with last post front w bone rear bushes ...

Front arm bushes or track rod end,probably on the drivers side.

Cheers
Davie