1. A system for automatic exterior and interior inspection of vehicles, said system comprising: optical imaging means for capturing an optical image of the undercarriage of the vehicle as it is being driven into a secure area; a backscatter mode X-ray camera for capturing an X-ray image of a luggage compartment of the vehicle as it is being driven into the secure area said X-ray camera being activated when the back wheels of said vehicle are detected from said optical image; a database for storing captured X-ray images; weighing means for obtaining a two-dimensional weight distribution of the vehicle, and monitoring means operable to facilitate activation of an alarm based on said captured X-ray images and said obtained two-dimensional weight distribution.