The Good ol' Police Cruiser. The Birth of Detective Adam Trooper.
As for Civilian Cars, I believe the Golf.
Ford Taurus 2010 for Police and Benz which got traded for a Prius
I think it was Ford Transit
Mustang, alright I guess..
On Cityrp1 It was that older Volvo. But on Limelight it was Audi RS4.