I'm still gathering more info on the P73 and P74 designations to see when they were first used. Also, there's also the P70 that I forgot to mention. The P70 is an extended version of the Crown Victoria that was first introduced in 2002 and that was built for taxi companies. There's about 5-7 on the site. But as soon as I get more info, I'll get back to you antp.