I completed it anyways yesterday, I was so mad, I did anything I could, change the radio, outfit, weather, time and nothing helped, I put radio off when doing the mission. The first two parts were easy as hell but the last one is hard. Mendez drives like a maniac and gets away. I couldn't believe it when I picked him up, ROFL afterward I drove carefully to save. And I did the whole storyline yesterday. High Wire was the only mission that took a lots of attempts and I wouldn't mind retrying the last part, but the fact that if I fail once I have to start it all over. It should just like "End of the Line" skip every part you pass because that would make it less annoying.
Unfriendly Competition did I pass first try. And Light My Pyre is only hard at the beginning where you got to protect Lance. He drives behind the Sentinel's like an idiot and always spins out my wheels, you got to be so careful that you can't shot forward on the cars.
The only problem I had with Domestobot was getting to Armando's safe. Whenever I'm going to it he orders me something. The code wasn't hard to find because I had watched it on youtube already
I think....
For LMP all I did on the second part was hide behind walls and toss some grenades it got many kills and loved seeing the cars getting wrecked there. I am fireproof so I can beat Armando with fist fight if you'd want.