Saints Row had a GPS system and free-aim. And online multiplayer (console).Scarface: Lock on with fine-tune, fleeing the police by escaping a radius
True Crime: NYC: Working public transportation, drivers ejected from their car on frontal impacts
Driv3r/Parallel Lines: Police officers have individual vision cones
Are there any other mechanics done first by other series?
The Simpsons: Hit and Run let you replay past missions.
Not a GTA clone, but IV's cover system was inspired by Gears of War.