The Maine state police have been using marked and unmarked Crown Vics on the interstate for a long time now. They've also recently started using unmarked late-model Mustangs. I've seen two in the past month.
If you've ever wondered where Cisco got the idea for ? completion in IOS, check out Origins and Development of TOPS-20. TOPS-20 also is the source of using C-v for quoting the next character when typing in several Unix shells, and with TENEX is the source of the T in tcsh.