In particular I would like to see the fences at Spa not be 'solid granite'. I think they should be able to be broken as a normal wooden barbed wire fence could in reality. Perhaps the material type can be adjusted so you don't bounce off the wooden fences but crash through them (knocking them down) instead. It will also allow cars to get back on track after having a paddock excursion. I think even giving them the 'hay bale'-type material would suffice until a better solution is found. Pure wish, would love to have deformable track-side objects such as armco and tyre barriers that can absorb energy from the impacting object and actually deform.