I recently put on Rota Subzeros (45mm offset)on a US MY02 and on uneven roads I get strong bumpsteer/wandering. Just wandering if its a function of the offset or something else. I know the offset is designed to put the wheel hub at the intersection of the two steering arms, but would the 5mm change from factory make this much of a difference?

 

this change together with any change in tyre size could well have the effect you're describing!
were any other changes made at the same time? and was your tracking/alignment checked at this time??
alyn - as performance