ok so the car has never had any suspension problems and never had anything replaced other than the bmw inspection. a while ago i put on 17 inch r72 rondell rims mounted with khumo exta mx tires, they were usedbut in pretty good shape. its a parralel setup but with 225 in front and 245 in rear. when i put them on the car got a bad shimmy that kicked in about 55 and stopped after 60 if i was by myself, if i had someone else it would not do it. since then i have lowered the car with h&r springs and koni adjustables, now the shimmy kicks in at 60-65 and only if i have someone else with me, never does it when im alone......................................wtf???? ??
any ideas other than the balance being off? still doesnt seem to make sense to me tho, just lookin for some feedback

Balance the tires first. That'll tell you if they are out of balance or you bought bent rims. If there is still a shimmy after that, you would have to check your upper and lower control arm bushings, sway bar links and center link.