A crossbar assembly for facilitating isolation of a sensor assembly from vibration of a payload mounting system on a vehicle comprises an outer crossbar segment, an inner crossbar segment, and an isolator. The outer crossbar segment comprises a payload mount interface operable to mount to a payload mount, and an outer isolator interface operable to mount to an isolator. The inner crossbar segment comprises a structure interface to mount to a structure, and an inner isolator interface operable to mount to the isolator. The isolator can be supported by the outer and inner crossbar segments. The isolator comprises an elastomeric component operable to elastically deform in response to relative movement between the outer and inner crossbar segments. The isolator operates to partially decouple the outer crossbar segment from the inner crossbar segment and dampen vibrations propagating between the outer and inner crossbar segments.