The reason that body panels are dentable is that denting helps absorb impact energy, and replacing a body panel or two is cheaper than totaling the entire car d

The reason that body panels are dentable is that denting helps absorb impact energy, and replacing a body panel or two is cheaper than totaling the entire car due to a dented frame creating a risk of structural failure. IOW, it's a feature, not a bug. It's also safer for the other party in an accident, since the vehicle(s) will absorb crash energy that would otherwise be transferred to the occupants/pedestrian/cyclist. Given Tesla's abysmal self-driving record (literally, more self-driving accidents, injuries, and/or fatalities than the entire rest of the global automotive industry combined), that's a fundamental consideration. Similarly, most cars have impact-resistant glass, but not shatterproof glass, for safety reasons. There are plenty of times when you want the glass to break.