I have to chime in here,
there is no way a pedestrian without proper training can even come close to guesstimating any car doing 100MPH on a surface street.
And before I go any further the word guesstimating is actually in my spell checker? Party on Wayne.
Having been a fire fighter, even that being during the early 1990's, I have been to countless vehicle fires. They are generally all the same in regards to witnesses, they stand by and watch, adrenalin starts pumping, things seem to happen quicker to their eyes as their brain struggles to take in whats unfolding by the time its already happened. One witness' account will vary from the next, its fact.
The last vehicle fire and accident I came across was just a few years ago around 2010 as I was driving home from work late at night. I had seen lights flash and BTTF style burned road about half a mile ahead of me. In my mind it didnt look like a car accident but in reality one vehicle had side swiped another at speed forcing it into the center divider causing it to flip as the first vehicle spun out to a stop. The vehicle that flipped did so at least twice that I could tell by the damage to the roof alone. As I slowly drove up to the scene and pulled off to the side, other passer byes drove off as the flipped vehicle was obviously starting to catch fire on the under carriage. Only one other person had stopped whom happened to be a fire fighter in training. We both asked the other accident vehicle if they were the occupants in the other car as it seemed this had happened at least five minutes prior and the vehicle now catching fire looked empty. In fact the accident had just happened and those people were driving the other vehicle, the occupants to the other vehicle on fire were still in there. This was two young girls, their mother (a rather large woman) and a male driver (again rather large). With the way the roof was collapsed no doors could be opened so I bent down the passenger window frame to try and get the mother out as she wasnt breathing. At this point the fire had entered the cabin as I could smell skin burning, it was the feet of one of the girls, as her sister began to awaken. We couldnt bust the window open to get the one girl out until a tow truck driver brought over an axe. We snatched the first girl out but her sister, the one burning, was trapped by her feet under the passengers front seat. I went back to the passenger front door reaching in and yanking the seat forward as the other guy pulled the girl out. Apparently I had ripped the seat from the floor itself as thats what helped get the woman out after we pulled the male driver out, by his ears, over the seat and out the rear door. The guy was in so much shock he couldnt function as the interior fire started to engulf his seat.
This was all in less than a single minutes time. Car after car drove by and away, some people stopped to watch but did nothing, just watch. The mother had been revived by the guy that helped and then was airlifted to a hospital where she passed. I never seen or heard from those people but read about it in the paper clipping my mom found. I lost a pair of pants, a jacket to burn holes (a fire retardant flight jacket of all things), a pair of boots with melted soles and all the hair on my legs and arms up to and around the money maker. Im told by an onlooker as we pulled the man over the seat and out the rear window we were engulfed in flames up to our chests.
Vehicle fires are common in accidents, they engulf a car completely in roughly 60 seconds, witnesses are not always the best witnesses, onlookers rarely lift a finger to help those in need. Hell, some moron down the street yells at me when driving my 65 Falcon down the street at 30mph "slow down fxxxing mfxxxing axxxhole" and the limit is 35. People are iiiiiiiiiiiiidiots.