CMDR Heavenrun suggested this to me and I'm passing it along: Sensor shielded smuggling compartments. Half the capacity, but they'll beat low-end cargo scanners, and the higher-ended scanners have to get closer to get a definitive scan. Show up clean to the low-security cops, need to get a close approach for the more sophisticated cops, and still gotta be on your toes to haul contraband into high-security docks.