Here's an eye opening video to watch. This was the Silver STI driven by Robert Jekoz at Tall Pines this year: http://www.youtube.com/watch?v=LNeamTQywV4

Watch it right to the end. You can hear he's in agony while still in the car, and see him holding his lower back after he gets out. That's clearly a compression injury. He's okay now, for anyone that's concerned. But something like that could have been prevented, or at least improved.
From the performance graphs I've seen, the Leatt-Brace is the best at preventing compression injuries just like that. That sort of compression force is rare in other motorsports. But with all the jumps in rallying, even if you do land on the road, it can still sometimes be hard enough to cause something like that.
Yup, the more I think about it, the more I'm leaning towards the Leatt...