Update: Picked up the car after more than 2 weeks in the dealer shop. Upper and lower controls arms and other bushings have been replaced.Test drive with the shop menager and the service adviser...same banging. Droved together a demo(2010) and no banging.Drove an other LS model 2007, with 35K miles, no banging.My car has only 18K !
Contacted Lexus. They will have my car checked by an engineer next week .Will keep posted.