As long as you pass an AI wrecking in front of you, it'll count as a crash escape. There's no way of producing it, you'll just need to hang back and be patient.
I noticed that there are some races where the AI is more prone to crashing, like races that have roadblocks in them. Also, they're likely to crash if you guys are traveling at higher speeds. The problem is when you do tail them they will crawl to the same speed you're going, but if you accelerate just a little you'll end up passing them. Unlocking the pro upgrades for the impact and aero mods showed me how apparent the AI rubber bands.