I have a higher mileage sc400 (170K) and I went to test drive a lower mileage sc400 (100k) and it has a clunk in the driver's side rear when it goes over bumps. My car never had this problem (front lca's yes). Is this a common problem or will it be hard to narrow down (dealership just told the current owner the car is old and will do that), well mine doesn't and I don't want it to. The rear has multiple arms/bushings and I don't know if there is a common weakness like the front lower control arm, car has had struts within last year. I would hate to not buy this one owner, life-long dealer maintained car because i don't know what this is, and what it will cost to fix.