From Roundel 4/01 (BMWCCA): Some 3.0-liter X5s with automatic transmissions may exhibit a steering wheel vibration at idle, in gear (drive or reverse), and with the air conditioning on. Only if you are experiencing this problem, dealerships will install a vibration absorber, pn 32 30 4 011 368, and a new/modified lower steering column cover, pn 32 30 4 001 366, to reduce the vibration.