Look up Brosseau v. Haugen case law. There's extensive precedent for self defense for federal agents when people drive their car recklessly near them.
Note that in Brosseau v. Haugen, the court ruled explicitly that even a car driving AWAY from an agent can be considered an imminent deadly threat, and that firing multiple times can be justified.
In fact, that case was even murkier because the target was shot in the back (versus getting shot through the windscreen into the chest), and more bullets were discharged, and the car was further away!
Note that in Brosseau v. Haugen, the court ruled explicitly that even a car driving AWAY from an agent can be considered an imminent deadly threat, and that firing multiple times can be justified.
In fact, that case was even murkier because the target was shot in the back (versus getting shot through the windscreen into the chest), and more bullets were discharged, and the car was further away!