If you are already using your car as a weapon and you are about to go assault more officers or civilians with the deadly weapon then "yes" -- it is perfectly legal and acceptable for police to shoot the driver.
I rephrased the question you should be asking... "So it legal to shoot someone for driving at another car?" In some states, yes it is. In Florida it is called "using deadly force to prevent a forcible felony". And driving directly at another car with someone inside it may cause great bodily harm or death, which is a forcible felony.
You better go watch the videos --- he was shot after running over cops and then driving towards more cops.
I am just citing what the DA and SBI stated. If you have a problem with it then go contact them for a further explanation.