Old News, but maybe beneficial on # of cars. My guess would be anywhere from 10-20 now.
Item #1 RANDOLPH COUNTY (NC) SHERIFF'S OFFICE TO PURCHASE SQUAD CAR LAPTOPS
The Randolph County (North Carolina) Sheriff's Department plans to spend $180,000 on new equipment, including 10 squad car laptops, using seized drug funds and other forfeitures. The computers will be the first for the department, and will allow deputies to perform records checks without the need for dispatchers.
[Source: "Deputies Tap Into Technology; The Randolph County Sheriff's Department and the State Highway Patrol Will Use Mobile Computers to Increase Safety and Reduce the Number of Delays" by Denise Becker; Greensboro (NC) News & Record (High Point/Randolph edition) October 17, 1999, Pg. R6]