process of elimination from cheapest/easiest up - firstly what did you change to make it happen. Try other wheels, if its still there its not your wheels, (if it isnt, it might be your tyres) - then try without spacers (if the wheels fit) - then try other tyres... pain in the bum, i know, ive been there, but there is nothing worse than a poorly handling car, especially if it was ok before.