Grand Theft Auto 3
Here is the Lamborghini Diablo Pursuit, a detailed and well made car that will either replace the police car or any other car of your choice within GTA III.
Here is the Beta Cop Car Double Pack, this includes two vehicles - The Police Car and a Riot Vehicle, these will either replace the Police Car and the Enforcer or any other cars of your choice within GTA III.
Here is the police version of the Mitsubishi Lancer Evolution, this car is fairly detailed and has low detailed textures. This car will replace the police car or any car of your choice within GTA III.
Here is the Citroen Xsara Picasso LCPD, a detailed police car that will replace any car within in GTA III.