set it to a collision that's double the actual speed they were driving while caught texting. (In other words, head-on collision with another vehicle doing the same speed
Actually, that is false. A head on collision with a vehicle of the same mass would be no different than the indestructible brick wall. Yes, when you add a second vehicle to the mix, you are doubling the amount of moving mass, but the absolute speed remains constant. In the end, the delta V is the same in both scenarios: X to 0. Now that we know that the delta V is the same, we just have to account for the deceleration rate, which is basically the same as the duration of the impact (crumple zones and all that). Since we have identical cars, they will deform at the same rate, acting as each others' brick wall. Once they collide, they would be exerting identical force on each other, so the front bumpers would remain in the same location, just like the brick wall. Since the front of your car can no longer move forward, the collision happens, and the body of your car absorbs the energy required to decelerate to 0. The energy released when two cars collide is doubled, but it is also spread over twice the area (ie, now you have 2 wrecked cars).
"Being against torture ought to be sort of a multipartisan thing." -- Karl Lehenbauer, as amended by Jeff Daiell, a Libertarian