Among other things, the act directs the Secretary of Transportation, in consultation with the FBI Director, to obtain vehicle theft and recovery data from the most reliable sources, so as to identify vehicles with high theft rates and assess the act's effectiveness. Vehicle theft data are contained in data bases maintained by the FBI's National Crime Information Center (NCIC) and the National Automobile Theft Bureau (NATB). This review, which was performed between October 1985 and September 1986, interviewed key persons with knowledge of the act or the NCIC and NATB data bases; drew samples from selected police agencies and insurance claims offices; reviewed reports, procedures manuals, and other pertinent documents; and compared sample data to data in NCIC and NATB. The National Highway Traffic Safety Administration currently uses NCIC data on vehicle thefts, both NCIC and NATB data on the number of recovered stolen vehicles, and NATB data on the condition of recovered vehicles. This procedure generally uses the data bases according to their particular strengths, although there are some problems pertaining to the completeness and accuracy of the data used. 10 tables.