The first and most obvious point to make is that avoidance of these situations is the ultimate goal. So if possible, change directions to avoid the situation. Keep in mind, hitting a person with your car (even a slight bump or nudge) to simply clear a traffic obstruction is not recommended and could result in charges to include battery, aggravated battery, criminal recklessness, or even much worse, if your actions arguably result in the death of an individual. However, things change when there is an attack on your occupied motor vehicle. Unfortunately, we cannot predict how all prosecutors or juries will view every possible scenario. However, we can give you some guideposts to keep in mind.
With respect to the law in Indiana, our “Castle Doctrine” would be applicable to many scenarios involving a person’s occupied motor vehicle. Although many people understand Indiana’s castle doctrine to be applicable to your home, it also has application to your occupied motor vehicle. Indiana’s “Castle Doctrine” is at IC 35-41-3-2(d), and indicates, in part, that a person is justified in using reasonable force, including deadly force, against any other person; and does not have a duty to retreat; if the person reasonably believes that the force is necessary to prevent or terminate the other person’s unlawful entry of or attack on the person’s dwelling, curtilage, or occupied motor vehicle. . .
Also, Indiana’s general self-defense statute at IC 35-41-3-2 should be another guidepost to keep in mind. It provides, in part, that a person is justified in using reasonable force against any other person to protect the person or a third person from what the person reasonably believes to be the imminent use of unlawful force. However, a person is justified in using deadly force, and does not have a duty to retreat, if the person reasonably believes that that force is necessary to prevent serious bodily injury to the person or a third person or the commission of a forcible felony.
Indiana law does provide for the lawful use of reasonable force, and in some circumstances deadly force might be considered reasonable. Ultimately, your actions may be judged by a jury as to whether they were reasonable under the circumstances. If you have to use your car to move through a crowd, use the least amount of force necessary to clear the scene. Greg Ellifritz has an excellent article we would suggest you review that may help you visualize various scenarios and appropriate responses.. His advice can be found here: https://www.activeresponsetraining.net/surviving-mob-attacks-on-your-vehicle.