Do NOT use urethane bushings on lower control arms. No matter what you're told. Use Moog rubber bushings.... The only thing keeping the lower arms in place are the torsion bar clips, and the strut rod and bushings. AND the fit of the lower bushings. Urethane, to me at least, seem to be able to slip and slide out of place...
IIRC my kit was mostly poly, but came with both for those because others were having issue you described. I agree, the poly just seemed like a bad application. Used the rubber type.