After I install lowering springs, should I back off the control arm bolts, bounce the car and then tighten the bolts? Seems to me that the control arm bushings would have an easier life if one did that.

BMW makes us put weight in the front/rear seats and trunk before tightening control arm bolts after replacing bushings.

 

On the S197, the control arms and panhard bar are supposed to be torqued with the suspension loaded.