Here is the list of all unique vehicles you can find in Watch Dogs 2. Once you have them, they become automatically available in the Cars on Demand App, meaning you can call them in at any time during your adventure in San Francisco Bay area.
In total there are seven unique cars, one from each category: Heavy Vehicle, Muscle Car, Sports Car, Off-road, Performance Car, Motorcycle and Standard Vehicle.
Danger MobileCategory: Heavy Vehicle
Flip WagonCategory: Standard Vehicle
Ice CubeCategory: Sports Car
Mountain KingCategory: Off-road
The vehicle is in a closed area. To unlock the gate, you need to hack closed circuit terminal located inside this area.
You can use RC jumper (required research: Remote Ctrl: Enhanced Spring) and jump over the fence here.
You can also use nearby lift and jump over the gate.
Rainbow MissileCategory: Motorcycle
The vehicle is standing by the wall on the back of the property in a restricted area, but it is guarded by one guard and one robot only.
To open the locked gate you need to unlock this closed circuit terminal.
The DangerzoneCategory: Performance Car
The vehicle is inside a locked garage in the underground parking lot.
Go outside the parking lot and find the vent shown in the picture below. It leads to the right, locked garage with closed circuit terminal. Use the jumper to get there.
Hack a vehicle (required research: Vehicle Hacking: Directional Hack) and use it to destroy the wooden board blocking the access to the terminal. Unlock the terminal.
Now you can open the left garage door and get into the car.
To get to the right locked garage, you can also use the vent located in the parking lot near the ceiling. To do it, you need to park one of the cars (higher is better) in the right corner and then use a the jumper to reach ventilation shaft (required research: Remote Ctrl: Enhanced Spring).
WreckerCategory: Muscle Car
To get this vehicle, you need to use the quadcopter, take control over the car and drive it out of the container (required research: Vehicle Hacking: Vehicle Directional Hack).
If you don't have the quadcopter yet then you should hack the nearby crane and use it to get on top.
