Explosive Liaisons

For this challenge, the player must trick Robert Knox into eliminating Sierra Knox.

• Infiltrate the Security Building, which is to the right of the Event Entrance starting location.
• Take the Evidence Locker Combination note in the main room (the one where you can disable the surveillance system and that has three guards in it, on Professional difficulty at least).
• Open the evidence locker in the back room, and pick up the Car Bomb and the Note From Evidence Locker within.
• Infiltrate the Kronstadt Garage, pacify a Kronstadt Mechanic, and disguise yourself as one.
• Initiate a pit stop for Sierra Knox, making sure you choose the middle option (which has you attach the Car Bomb to Sierra Knox's racecar).
• Use a Coin on one of the payphones scattered around the mission area to call Robert Knox. For example, there is one such payphone close to the Event Entrance starting location, which is relatively close to where you need to go next.
• Notably, if too much time has passed within the mission, Robert Knox will decline to meet with you, saying that the race is already over (even if it technically isn't yet). Restart the mission if this occurs.
• Meet Robert Knox at the northern overpass (note that down is North on the map) and give him the Car Bomb trigger.
• Wait for Robert Knox to detonate the bomb, which completes the challenge.

At this point, you can eliminate Robert Knox however you like, such as by pushing him over the ledge immediately. Alternatively, you can use this opportunity to complete the Shredding The Evidence challenge (see page for explanation, which includes potential spoilers).