This save has 139 out of 140 cars bought and unlocked. Do the last race activity being Race Activity 1 and you should get the 'Radio Active' achievement for completing 50 Activities. On a side note you will unlock the last vehicle in the process. Once your finish with the activity, go to any garage and purchase the last car to get the 'Petrol Head' achievement for purchasing all vehicles. Creditors to myself and hope this save proves useful. Also yes this save has a massive amount of will power so don't be alarmed. I used the Driver San Francisco save editor. Again good luck with this save and enjoy.