They are used to x-ray passenger cars as well as lorries for contraband, especially illegal shipments of alcohol, tobacco, and narcotics. This will make it much easier for authorities to locate secret compartments.
Officials believe the x-rays will have a huge effect in the fight against smugglers. Currently they estimate that only a tenth of illegal shipments are caught.
Not every vehicle will be scanned by the machines. Border officials will only scan vehicles they determine are a in a high-risk group for smuggling.