Overview
How to get infinite money/race certificates
This video shows how to farm race certificates
This will become available after unlocking the final mission.
1. Buy some Pulse Shots. They will one-shot enemy cars on any difficulty.
2. Head over through the Authority Bridge, pass the gates and turn left. Kill the guy who is sitting there.
3. Turn around and wait for this guy to respawn. Position is shown in the video.
4. Go back to the Subway Town and get your reward.