If you want to unlock token cars, then you can do it very easily by following these steps.
First download this tool from here
Now follow these steps or you can watch this tutorial video here.
Step 1:- Run the tool.
Step 2:- Open Asphalt and drag or insert in second window as shown in video.
Step 3:- Open First car of Class D i.e. Dodge Dart Gt which is free from Asphalt for all the users, max its upgrades. You'll not be able to unlock cars until you MAX it.
Step 4:- Click on start.
Step 5: - Click on Apply next to any car you want to unlock.
Step 6: - Open Asphalt 8 and click on Dodge Dart GT and you'll see a price tag of zero. Buy the car and max its upgrades.
Step 7: - Close Asphalt, re-open Asphalt and your car will get unlocked.