one bike? In the vehicle. Just my opinion. Been rear ended a couple times. Don't know if insurance would cover that? I know it wont replace my vintage bikes. Roof rack? YOu can't see whats above you. Out of site, out of mind. Ive seen it happen to 2 friends. If I pull the wheels off of my 60cm Merckx, I can fit it into our Yaris. Safe & sound! If we get hit that hard, The bike will be the least of my worries...