Taxi Bomb is a mission in Free Ride Extreme. It can be started by talking to the man in the New Ark Harbor. The objective is to drop taxis in the water before time runs out, lest they will explode. This mission is quite difficult, because you need to get the taxi, drive it to the nearest waterfront, find another car, and then push it in the water. Together, these things will cost a lot of time. It takes skillful driving and a bit of luck to complete this subquest.
The first taxi is located in the New Ark Harbor, the second is in the construction site in Hoboken, the third is parked in front of the State Capitol on Central Island, and the fourth you can find in the parking lot of the harbor in the Works Quarter. If you manage to get all of the taxis in the water on time, you'll receive the bonus car (Manta Taxi) that is parked underneath the West Marshall Bridge.