Actually, just brought it in to the BMW dealership again, 3 technicians including the shop foreman were on it, and they thought it was most likely the guibo (flex disc) behind the trans. Had it replaced, vibration still present. Had all four tires roadforced under 18lbs, no rims bent evident, all four front lower control arms replaced, strut mounts and strut bearings replaced. Vibration still present. Most heavily noticeable at 60mph with my foot barely on the pedal. Ugh. I am at a complete loss for words. And find this very frustrating to say the least because it is still not resolved. Any previous experiences and suggestions??