I expect energy dissipation scales in a similar way... e.g. I'd expect a head-on crash of two light cars to be roughly comparable in severity to occupants to a head-on crash of two heavy cars. Is my intuition off here?
But the smaller cars are probably more carefully designed for "crunch" zones, preserving their occupants by maximizing the effect of available material. The nominal energy involved vs Cars would simply scale as Mass of SUV in Cars.