This is the official Need for Speed: Hot Pursuit car list. Hot Pursuit features 80 different cars (DLC included), but not all cars have a Racer and a Cop version: some cars are exclusive to one side of the law.
EA Games statement on the cars of Hot Pursuit:
Need for Speed: Hot Pursuit features the hottest cars, with absolutely no "fillers". You'll be able to tear around the scenic routes of Seacrest County in some of the most powerful rides on the planet, many of them appearing for the first time ever as police vehicles. You'll be able to take down the racers behind the wheel of a cop-spec Pagani Zonda Cinque, or trade your badge for the thrill of outrunning Seacrest County's Finest in a Dodge Viper ACR. We hope you enjoy driving these hand-picked machines as much as we did selecting them and crafting them into Hot Pursuit.
Official car list
a) Racer version available only to owners of the Limited Edition.
b) Racer version available only for the Xbox 360 through a promotion with Dr. Pepper.
c) These cars are available only through DLC.