Actually, a smart car would be a good car to have an accident in. For 2008, it earned top ratings for front and side impact and second highest rating for whiplash from rear collision.
I think if it had knee airbags (no joke!) it might have scored higher.
Our Peugeot has them to prevent lower leg injuries on the bottom of the dash as inertia takes the lower leg forward into the plastic and the rail behind it that goes from side to side of the car.