The Preliminary Semiannual Uniform Crime Report was released at the end of February, revealing a decrease in motor vehicle thefts. This FBI report covers the first 6 months of 2018, in comparison with the first 6 months of 2017. From January to June of 2018, vehicle thefts decreased by 3.3 percent.
By region, the largest decrease in motor vehicle theft was found in the western United States. When considering population size, the largest decrease was found in cities with population size ranging from 25,000 to 249,999.
The full report can be found here.