Size does matter. Simple physics - momentum. A smart car might have more safety stars to, lets say, a 1970s F-150, but if you hit an F-150 in a Smart, good luck to you. All those things won't count when a car more than twice the weight off yours 'swallows' up the momentum of the small car, leaving minor damage to the large car, and devastating to the small. Crumple zones are designed to increase the time of the impact, nothing more. It won't increase the mass of the car. And yes, I've had experience, unfortunately, of being involved big vs small car. Small car (lancer) written off, big car (fairmont) just bumper and radiator damage. I've known people who had accidents in Discoveries too. They had bumper damage, the other car had to have the whole back replaced.