On the one, I don't like the idea of people thinking they have free reign to mow people down in their cars. On the other, we have seen some really terrible things happen at protests where angry crowds, cars and assault weapons were involved. These are not a good combination.
There was the one in Austin last summer where people swarmed an Uber driver and attacked him, and (because of course this is Texas and everyone is armed to the teeth), the protesters were carrying AR-15s, and one guy pointed his assault weapon at the driver, and of course, TEXAS! the driver was also armed and shot the protester dead, and sped off (where he could have killed lots of people in the crowd and only by some miracle didn't) and another complete idiot also armed to the teeth (TEXAS!) shot into the crowd after the car where HE could have killed lots of people in the crowd and the only miracle of the day was that the only person out of all those present killed was the guy with the AR-15. It could have been so much worse.
Crowd of protestors+assault weapons+middle of road+terrified motorists=not a good combination
There have been protests in the middle of interstates where protestors have gotten killed. Protests where drivers have been attacked. Having a crowd of people carrying assault weapons surrounding your car screaming and banging on the hood would make almost anyone go into lizard brain mode and floor the accelerator, thinking they were about to be killed. I get that people need to protest, but for the safety of the public AND the protesters, the middle of highways and places where the police cannot effectively keep cars from inadvertently coming across the protest and getting attacked is NOT a good place to protest.