If the car is new then you have to go through a different check down. Is the driver old? Does it look like it is new driver? Is there a yellow sticker that says, student driver, have patience
Now if the car looks older, give them the benefit of the doubt that the car has issues.
Still though, if there is a long line behind you and you have car problems and can not speed up at least min speed, just pull over and let people pass you.
then you gotta see that you are a california driver and we tend to drive a tad faster here than the midwest. I drove from MN to wis with my mn family a few times. Highway speed 65? So I thought and I'm so used to the rate of speed but it is actually 55. I got scolded by my old uncle a few times. I really did not know.